Dimming lights/low voltage question's....

[AmIGrand]

Since the question keeps coming up in threads, and Steve and myself, and numerous others with whom I am regretably less familiar keep replying to them as the questions arise, I am starting this thread as a reference for people who somehow haven't read the FAQ's or found the answers they seek in a search. Feel free to reply, but this wasn't meant to start a discussion, only provide information.

Any guru's please feel free to back me up so that others know this is accurate and credible, or to expound on any part of it if, in your expertise, you find any part of it lacking.

Not to be nasty, but if there be any individual who should feel compelled to disagree with this info based on what their "friend who knows a lot about this stuff" told them, I would ask said individuals to refrain from posting here without doing some heavy duty homework. This post is meant to clear things up for people who have heard different things from different sources and need help, not add to their confusion on the issue. That said -

The most frequently recomended step to help with a low voltage situation is to add a capacitor of one sort or another. This advice is given even by seasoned professionals in the industry. Unfortunately, it is more often than not the wrong advice.

Capacitors (caps) are a good thing - if they're used correctly. When added to an electrical system that can keep up, they provide the extra on-demand power a big amplifier craves. However, if the electrical system is already lagging, a cap helps until it's discharged, then it becomes one more thing for the already overworked charging system to keep up with. Once drained, a capacitor becomes a point of resistance in the system untill it is able to regain a voltage equal to or greater than that demanded "down stream", as it were. Since caps drain very quickly, and the demand that drained them in the first place will draw the current it wants with or without the cap, they do not recharge until the demand drops. So -

Make sure the alternator is in good shape. Then check the existing battery. If either of the above is wanting, replace it. If both are good, then add a second battery to reduce the load on the front end of the charging system. Upgrade the alternator if you are hard on your system to the point where even the 2nd battery is running behind. Once all this is in place, and your voltage no longer drops at the front, add capacitors as you see fit to bolster the amplifiers supply voltage. This is proper use of a cap.

Note that not all situations will call for the additional battery and/or upgraded alternator. If the power shortage is slight, as with a moderately sized amplifier added to a stock charging system in good condition and not overtaxed, a cap MAY be helpful. For most imports, that would be a sub amp fused at less than 40 amps, with few or no other additional components drawing significant power. There are no "exceptions" per se, but there are borderline situations where a cap may be benificial, and the preceeding was a VERY GENERALIZED example of such a situation.

As to what to add if you do in fact need to beef up the electrical system's foundation, here are some Cliff's Notes on what to do when.

When adding a second battery, try to mount it as close to amplifiers as possible. Avoid standard lead-acid batteries - for both safety and practicality. Gel Cell batteries (most popularly the Optima brand Red or Yellow Top units) are good, and will do the job. Redtops work best as a PRIMARY battery REPLACEMENT, Yelows are better as a second, dedicated battery. Drycell batteries (I prefer the Stinger brand, there are other very good ones out there) are better. They have a lower internal resistance, recharge faster, can discharge more current on demand, and are more durable.

Any time a second battery is added, the power wire connecting the two MUST be fused within 18 inches of BOTH batteries positive posts. A dual battery isolator or relay is not NECESSARY, but is a very good idea. It is OK to ground the 2nd battery to the frame if you'd rather not run two wires through the car, but all system components should be grounded to the system batteries negative post (this is usually more convenient install-wise anyway). It is not in fact necessary to have both batteries be of the same type - they will be wired in paralell, so the resistance will therefor average out as far as the alternator is concerned, although the battery with the lower internal resistance will charge faster.

Upgrading the alternator can be done two ways, by having your unit rewound to a higher amperage, or by replacing it altogether with a high output type unit. The former is less expensive, but typicaly less reliable, the latter usually more reliable - but MUCH more expensive. I am not going into adding additional alternators here, it is VERY seldom necessary, and if you need it, you need more help than would be useful here.

I REALLY hope there won't be many questions remaining after this, I tried to make it easy to grasp. Sorry it was so long, I hope it will be worth it!! :)

[underthegun]

What about upgrading the stock batt/alt wiring to a bigger size? Doesnt this have any benefit?

[AmIGrand]

Ah - he finds the part I left out. Sorry about that!

Yes. Upgrading the factory power wire and ground straps is very effective, even without a big audio system or other draw. Voltage gains of .5 volts are usually realized simply by replacing the alternator wire and the alt and batt ground wires with quality 4 ga.

Good call!! :thumbs:

[underthegun]

Any tips, tricks to offer on how to do this properly? I remember a post stating that you shouldnt "replace" the alternator wires, but to add another...

[AmIGrand]

There was an individual who wasn't sure where to take the wire. He was concerned about going to the fuse box first and then the battery, or battery and then fusebox. In all reality, it doesn't matter, they're in a parallel circuit. He finaly left the stock wires in place, and added an additional wire (4 ga) straight to the battery. Nothing wrong with that, but nothing wrong with replacing the stock wires, eiher (well, warranty issues, if they wanna be jerks about it).

[iceman]

Originally posted by AmIGrand
There was an individual who wasn't sure where to take the wire. He was concerned about going to the fuse box first and then the battery, or battery and then fusebox. In all reality, it doesn't matter, they're in a parallel circuit. He finaly left the stock wires in place, and added an additional wire (4 ga) straight to the battery. Nothing wrong with that, but nothing wrong with replacing the stock wires, eiher (well, warranty issues, if they wanna be jerks about it).

It is involved and really really difficult to replace the stock alternator -> fusebox wire, because of the way it travels, and it enters a connector on the underside of the fusebox that you will never get a thicker cable into. Easier to re-run from the battery right to the alternator.

You can also re-run the small cable that goes from the battery to the + supply on the underhood fusebox with 4ga, I did that, it takes about 2 seconds.

[Cliff]

Originally posted by iceman


It is involved and really really difficult to replace the stock alternator -> fusebox wire, because of the way it travels, and it enters a connector on the underside of the fusebox that you will never get a thicker cable into. Easier to re-run from the battery right to the alternator.

You can also re-run the small cable that goes from the battery to the + supply on the underhood fusebox with 4ga, I did that, it takes about 2 seconds.

Are you saying that running a 4 ga wire from the battery to the + terminal on the engine fuse box is just as good as running a 4 ga wire from the alternator to the fusebox?

[iceman]

Well I'm saying that you are not going to be able to replace the wire that goes from the fusebox to the alternator with 4ga, it's impossible. You can, however, re-run fron the alternator to the battery, and also re-run the battery-fusebox connection.

There really are 2 distinct different wires... You could go from the alternator to the fusebox if you wanted, but you still have the "small pipe" to the battery.

[underthegun]

I think it would be a good idea for someone to post a how to on this...it would def. clear alot up...

[tbone]

What would a slight drain be classed as?

My lights dim quite a bit (like 30-35%) on a thump; but do not if I rev up to 1500rpm or so. My battery voltage seems to wonder with the weather but that’s it, it always seem to return. This seems like it might be a slight drain, but I'm running nearly 800 watts?! That’s a lot of drain. I mean I know the equipment is crap but... would a capacitor help me? How big? Should it be wired on the other side of a diode to prevent flash back if it ever burns?

I hate to be a dummy but if I knew everything I'd probably be god (no blasphemy intended)


Your electrically ungifted reader.

Steve

[AmIGrand]

It's a matter of current draw. At higher RPM, your alternator turns faster & produces more of it, so your lights don't dim. If the total amperage rating of all your amplifiers is less than 60 amps, you are probably OK with a cap. Less than 30, you shouldn't even need that. Over 60 you want to start considering a second battery or a beefed up main one at least, over 100 a high output alternator would be a good idea in the long run.

A diode would choke power too much. For small applications (under 10 amps or so) they are fine, but not here.... Should the cap fail, the fuses in/on the amplifier will protect it sufficiently.

[GTkid]

here is a list of questions to any who feel the need to answer

what is the (amperage?) on the stock alternator

for a 90 amperage what would the best route be? im thinking optima red top

ok nevermind class over.

[AmIGrand]

Stock alternator is 90 (I think) on the 2.4, and 105 on the 3400.

If the combined rating of amps is 90, and one of them is powering highs, you're OK with the stock setup and maybe a cap. If the 90 amp rating is jsut the sub amp(s), an upgraded or seconf battery would be a good idea.

[brian]

I dont believe a second battery with our stock alternator would work, I don't think it could handle the resistance of the two batteries and would blow out. And upgraded battery would be good, but for a second battery youre going to need an upgraded alternator first.

[AmIGrand]

I don't know where this comes from, but this is the second or third time we've been here....

Adding a second battery does not significantly change the load to the alternator.

I have done DOZENS of systems with 2 batteries on the stock chrging system in lots of different cars - including GA's - and NEVER had a problem.

[currentman]

As an automotive instructor teaching advanced electrical systems, I would like to put in my 2 cents. When adding a second battery, it is wired in parallel. According to Ohms law, the more circuits you add in parallel, the LOWER the resistance, and your total resistance will be lower than the resistance of your smallest branch. (such as 2 4-ohm speakers in parallel have a total resistance of 2 ohms) Therefore, 2 batteries wired in parallel will have a lower total resistance than 1 battery alone. and before anyone asks the question, if you wired them in series, you would have 24 volts instead of 12

[tbone]

Well I just went a dropped most of a pay check on stereo components, I'm still running the same 2x 250 watt (20Amp) amps pushing the same 2X10" bandpass and the same 600 watt (40amp) pushing the same 15, but I added a 24v 1 farad capacitor (as everyone seemed to agree (including the sales man and i doubt he would have passed up the opportunity to sell)) But when I added I rewired from an 10 gauge wire run from the inside the fuse box to a 4/8 gauge from the battery terminal, now my light nearly turn off at an idle. They were like 30% dimming before. My battery voltage still seems to be stable but still this is not good, not after $150 on a capacitor and $250 on wire.
But on the upside when it really hits it hurts.

[AmIGrand]

Why are you running two different subwoofer systems?

[tbone]

Well the Band pass only hits to about 40 Hz, and the 15 will hit as low as 18hz. The GA trunk only seems to produce one strong antinode at about 52hz so I'm not complaining (I think it sounds great) and there is not detectable node.

But that not the point of my question, the 1100 Watts wasn't dimming to bad before the cap and now I can feel the car shudder like it's going to stall.

[AmIGrand]

If it's reacting that badly, you may have a bad cap, or there may be another problem. With the car idling in park and the parking brake on so the DRL's are off, with no other accessories running, test the voltagfe at the battery terminals with the system up loud. If it dips below 12 for more than a second or so, a new and stronger battery is a good idea. Have that cap looked at either way, though. 80 amps of combined current shouldn't drain the car that badly, but that's enough current to justify an upgraded battery in addition to your capacitor.

[silentalero]

Ok just found this topic and maybe you guys could help me out. Now under my hood i have a yellow top w/ 0 awg wire going straight to my amp..the amp is a 1500w digital beast (mtx 81000D). Anyways, I was considering getting a cap, but not sure if it would even hold up to the amount of power I need. Im powering 2 audiobahn 1000w subs, and even on the eway doin 80mph, my lights still find there way to dim. And honestly Im not even using half the the amp's tru power. I do have a 2nd yellow top, and I am considering putting it in with an isolator, but I would rather not if its not necessary. For the mostpart my lights dim about a good 50%-60% when the bass hits. and help is appreciated

[AmIGrand]

The 81000D is one f the hungriest amplifiers on the market, with current consumption well in excesss of 150 amperes at peak output. With anything else on, or heaven forbid another amp, your system will be unhappy with or without the second battery, depending on your listening habits.

That said, adding the second battery with a good dual battery relay (I recomend the Stinger SR-200, $69.95 retail, under $50 if you look) will drasticly reduce the dimming if you don't jam on it ALL the time - the additional battery will drain "first", providing a buffer for the rest of the system. If you jam on it all the time, the charging system will never "catch up", and the seconf battery will eventualy drain, making it an oversized cap at best (and no, a cap ain't gonna do much for you here).

Your best option will be to upgrade the alternator. Adding the second battry will help, and doing both (especially if you already have the extra Yellowtop....) would be best. Failing that, the second batt will help, but a bigger alt reallyt ought to be part of the picture. I like Mr. Alternator (http://www.mralternator.com) myself, and I'm sure their are places local to you that could help. Expect to part with around $300 with shipping and whatnot.

[silentalero]

what about reaplacing the wire coming from the alt to 0 awg to the batt? I heard that helps some

[AmIGrand]

It will help a little, yes, and I would definately recomend doing it either way - although 4 awg might be easier. ;) But it won't be nearly enough to fix the problem with that beast in the trunk! :p

[silentalero]

and just to think i was considering adding another one of these amp and 2 more subs, lol


the thing i like abou thte 0 awg i use is its extrememly flexible, and its threaded alot thicker than normal 0 awg power wire, because i get it from a welding shop. Since welding wire is used to have more current, it actually pulls alot more current than standard wire.

cant complain when i only pay $4 a ft for it to

[AmIGrand]

We did a system in a Camaro with 6 of them, one each to 6 12W7's in a wall. Add three PPI amps for the highs.... 2 alternators and 7 batteries, and it still wasn't REALLY enough. lol

Upgrade your alternator. Add the second batt as well if you like - can't hurt! :thumbs:

[grass]

Originally posted by AmIGrand
We did a system in a Camaro with 6 of them, one each to 6 12W7's in a wall. Add three PPI amps for the highs.... 2 alternators and 7 batteries, and it still wasn't REALLY enough. lol



good god

[silentalero]

omg :eek: :eek:


what was the spl on that system???

[AmIGrand]

I don't recall exactly. It didn't meter out all that well, really, phase problems when the car was closed. The guy didn't want certain things done that needed to be done, so it wasn't really up to our standards if you ask me. Still, te first time we fired it up in the insall bay with the doors open, it was loud enough to knock the rearview mirror off the windshield - of another car parked 20 feet away getting a deck installed. You've heard the story before, grass, before the crash.... The owner has had to replace his windshield several times - it's OK until he gets even one litle rock chip, than it's connect-the-dots across the glass if he turns it up. lol

It actually wasn't quite as badass as the 9 12's in the Grand AM SE I've mentioned, not to mention the 12 15's in a chevy full size truck. Any UT members may have seen one of those two on State in SLC - or at least heard them.... :D

[GTluver]

Originally posted by silentalero
Ok just found this topic and maybe you guys could help me out. Now under my hood i have a yellow top w/ 0 awg wire going straight to my amp..the amp is a 1500w digital beast (mtx 81000D). Anyways, I was considering getting a cap, but not sure if it would even hold up to the amount of power I need. Im powering 2 audiobahn 1000w subs, and even on the eway doin 80mph, my lights still find there way to dim. And honestly Im not even using half the the amp's tru power. I do have a 2nd yellow top, and I am considering putting it in with an isolator, but I would rather not if its not necessary. For the mostpart my lights dim about a good 50%-60% when the bass hits. and help is appreciated

thats exactly my problem......my lights dim no matter what..... :mad: :( i have upgraded alternator, to a yellow top, 4 ga. wire, 1 farad cap (piece of crap just adding weight to the car )......btw......my system consinst of 1800w Autotek Mean Machine amp, 2x12" Fosgate Punch subs, Panasonic 48x4 deck....i have heard from a nice, reputable stereo shop ( not where i installed my stereo) that a 15 Farad cap should fix the problem.....since i upgrade just about anything else that needs to be upgraded....heres a pic of a 15 farad cap......the brand i will be getting it is Aluma Pro tho........ www.AlumaPro.com

[GTluver]

Originally posted by GTluver
thats exactly my problem......my lights dim no matter what..... :mad: :( i have upgraded alternator, to a yellow top, 4 ga. wire, 1 farad cap (piece of crap just adding weight to the car )......btw......my system consinst of 1800w Autotek Mean Machine amp, 2x12" Fosgate Punch subs, Panasonic 48x4 deck....i have heard from a nice, reputable stereo shop ( not where i installed my stereo) that a 15 Farad cap should fix the problem.....since i upgrade just about anything else that needs to be upgraded....heres a pic of a 15 farad cap......the brand i will be getting it is Aluma Pro tho........ www.AlumaPro.com

by the way......the subs are 1k watts each, the components are stock......for now....:p and yea.....my amp is not using half its full power :( :tool:

[AmIGrand]

Well, first of all - what is that amp fused at? If it's over 100 amps (which it better be to make 1800 watts) you need more than 4 ga wire. Secondly - who upgraded your alternator, and to what output level? It may not be up to snuff, have a shop other than the one that sold it/installed it test the thing. Lastly - That 15 farad cap is a neat piece, but what's it cost these days? Last I checked they we're over $300, and for that money, a Batcap or a second drycell battery would be both cheaper and more effective.

[AmIGrand]

Well, I have never seen anything from Mr Alternator do anything other than exactly what it was supposed to, so you should be fine there.

For $530 you could add TWO more batteries, and upgrade all your wiring, and do a LOT of stuff. No way in hell you should spend that much on a cap, 15 farads or not!

First - get some 4 ga or 0 ga from the alt to the main battery. A few bucks and a few minutes, done.

Next - upgrade the wire from the front battery to the back of the car to 0 ga. You could leave it at 4 with what I'm recomending, but 0 is better with that alternator.

Keep the Yellowtop up front for now, it ain't hurtin' anything. Get a Stinger SP-200 dual battery relay, about $60 retail, eeeeaasy to install. Make sure their is a fuse (recomend 200 amps) within 18 inches of the + terminal, blah blah....

In the trunk, add a Stinger SP-1700, retail is $379, but they can be had for around $300. It's a big, badass, drycell battry designed for SPL systems, it'll take the abuse without a doubt. You'll need another fuse back here, again within 18 inches of the + terminal. Yes, two fuses on the same length of wire from front to back - you have to protect against shorts from BOTH batteries!

A short run of 0 ga from the battery to the amp, fused for whatever the amplifier(s) need.

This will do better than the 15 farad cap. No more dimming lights, the ability to jam on the system with the car turned off without draining the starter battery, and for less than $500.

[Everclear]

ok where exactly do i connect the upgraded wire to on the alternator?

[Alkaholik]

ok my lights dim quite a bit even with the cap but no dimming while actually moving, I expect the dimmage since my amp is 3000 watts. It doesn't really bother me antmore

[gagt13]

my lights dim also..........its not so bad but its noticable. i got the kicker 1200.1 pushin 2 10"L7s..... i upgraded the battery to the rockford fosgate batt... i was wonderin wut esle i should do that would help and not be all the much money.......funds are tight after buying that.

[AmIGrand]

You guys need a high output alternator. gagt13 - that battery is a waste of money without an upgraded alternator with an amp that big. It'll help for the short term, but in a few weeks/months, you'll be right back where you started....

[GTluver]

Originally posted by AmIGrand
You guys need a high output alternator. gagt13 - that battery is a waste of money without an upgraded alternator with an amp that big. It'll help for the short term, but in a few weeks/months, you'll be right back where you started....

if you have a lot of bass, you will still dimm like a mofo after half past volume if u want the music that loud....i have an Optima yellow battery, 160 amp alternator, 4 gauge electrical wiring, 1 farad cap......u need a capacitor more then one farad....those one-farad caps are crap and a waste of money.....at least get an cap of 5-farad and u should be fine.....im getting a 15-farad one just 2 be sure :p .....

btw, if u want the most bang for your buck, get ALUMAPRO caps....the best, reliable caps out there......hopes this helps a bit...

[gagt13]

i planed on gettin a high out put alt. jus that thers so much to do w/ so little money

[Brendon]

I want to add a yellow top in my trunk... I have a conventional battery upfront, a 160amp alt, and 2 amps (one PPI 480watt & 1 AudioBahn 580watt). Will my current 4 guage wiring running from my battery to my trunk do the job connecting the batteries? It feels somewhat insufficient.

Also, what size fuses should I put on both batteries? I was thinking 120 amps.

[AmIGrand]

With those amps, I don't see the need for all that, but it certainly makes for a solid foundation!!

The 4 awg is sufficiant, the wire front to back only needs to hold the current that'll be recharging your rear battery. Due to resistance differences, most of the power pulled by your system will pull from the rear battery. Uprading it with a second run of 4 awg or switching to 2 or 0 wouldn't hurt though, with a 160 amp alt and all. If you wanna go to the effort, go for it - but I wouldn't say it's "necessary" per sey.

As for the fuses - I usualy go with whatever the alt is rated at, just because. So a 150 or 160 on either end would be my recomendation.

[Brendon]

It is pretty neccessary... I dim quite a bit at night without even cranking my system (my 80wat headlights and high output foglights don't help, I'm sure). Keep in mind, PPI's are VERY power hungry amps. And that audiobahn sucks quite a bit of juice too.

Just looked at the back of my amps... My PPI has two 40 watt fuses and my Audiobahn has two 30 watt fuses... so I think it's safe to say my system uses quite a bit of juice. (not to mention the 50watts rms that I'm feeding my tweeters).
So yeah, the more I think about it, the less I'm surprised that I'm having dimming issues. Hah.

[bubbajim]

Another suggestion to help reduce dimming that I haven't heard mentioned yet.. This has helped me in my previous car (base model '93 escort hatchback).

Check your ground cables. Don't neglect them. Run them as short as possible and as fat as possible from the amp(s). 4 Gauge is good, but I ran 2 gauge in my escort and the massive dimming I had from my 2500 watt system (135amps total) went away.

[NLooman]

I seem to be having the same problem that everyone else is having. Ever since I had added the Yellow toped bat. I had less problems with being able to start the car. A few months had gone by and I started to notice when I set my car alarm the horn was really quite. I just figured it was no big deal and went on with life. But the last few days the bat has been dead and I have had to jump the car even after turing the amps and everything off. I put my bat. on charge last night and I think that helped quite a bit. What Im thinking is that the alt can't keep my bat fully charged. So would adding that extra cable from alt->bat and upgrading the alt help me out in this case. At night when the lights are on, stero W/o the subs and amp on, and i try to roll the windows down the lights dim to about 30% and now and then the ABS light comes on. If someone could help me out that would be a big help. Also if I add that cable from the amp to the alt, do you fuse it or what all do you need to do? Thanks alot. Below is all the stuff thats in my car.

[AmIGrand]

Your alternator is dead or dying, and not charging the battery properly. replace it with a higher output model to prevent this from happening again.

[tonmarchelli]

ive been reading this thread for a while and it helps out quite a bit. but ive got a question that i havent seen anybody else ask yet. ive got a 03 grand am with a kicker SX 1250.1, two Kicker S12L7's wired with 2 gauge wiring. i plan to add a high output alternator and a seccond battery but i dont know how to install a seccond battery. can anybody out there give me instructions on how to install a seccond battery. im completely in the dark. mainly stuff like what battery is good, what kind of wire and procedures. thanks a bunch

[AmIGrand]

In more detail than was given in the thread....

It's very simple, really. Wherever the second battery is, there are only 3 things you really need - a power wire connecting it to the primary battery, a ground wire, and something to control the flow between the batteries.

Assuming the second batt is in the trunk, it'd be like this:

Run a large guage (4,2,or 0) power wire from the underhood battery positive terminal to the rear one, just like you would for an amp. Make sure there are 2 fuses on this wire, one within 18" of EACH positive terminal (on either end). Between the two fuses, usually under the hood but it doesn't really matter, you'll need a dual battery isolator or a dual battery relay. I prefer the relays, they're much less expensive and easier to install, and a true isolator is only necessary with really complex systems. Basicly the relay will wire inline on the new power wire, and have a switched power wire to trigger it. When the ignition is off, the relay is open, seperating the batteries. When the key is in the "on" position, the relay closes, and the two batteries are wired in parallel. Make sure the rear battery has a good clean ground wire of the same guage as the power wire, either to the frame or a long one to the ground terminal on the front battery - the "proper" way, but not necessary.

As for the batteries themselves -

The Optimas are a good option, Redtops are made for underhood duty, Yellowtops as the secondary. Using the same in both locations won't hurt anything, but if you're buying them anyway, get a Red and a Yellow. I'm a big fan of the Hawker AGM units, sold as Odysee, Stinger, and other names. They're a lot smaller than the Optimas, and offer a lot more options as far as battery size and power. Prices are a little higher, not a lot, though.

Hope that helped.... :thumbs:

[schizm99]

Thx AMIGRAND was waiting to find out about the relay!!! Maybe this spring when things thaw out here!!

[tonmarchelli]

wow that helps a lot, just one more question. how do i wire from the new battery in the trunk to the amp? does the whole setup from hood battery to amp go like this.
Hood battery->Fuse->dual battery relay->Fuse->trunk battery->fuse->amp
and then the ground just goes to any grounding point from both the trunk battery and also the amp. also what size fuse should i use? thanks for all the help

[Everclear]

Dont buy a red and yellow, buy a red and a red. The yellows are no good they arent really deep cycle batterys

[tbone]

Now I'm mad...
So I have just purchased an Exide Orbital extreme battery and run 2/0 gauge from alternator to battery, Battery to motor ground, battery to fuse box and 4/4 g from the fuse box to the amp. I no longer dim to black but I still dim the alt has already been rewound and measured at 145 Amp at 15000 RPM WTF is all I have to say.... I'm running a Sony mp-70 deck (20 Amp) a thump 600W amp (25 Amp){ I know its crap} and an MTX 6290D (775Watt) (40Amp) and a 1 Farad Cap and I am out of Ideas.

[AmIGrand]

Hood battery->Fuse->dual battery relay->Fuse->trunk battery->fuse->amp

Correct. Run a ground from the amp to the rear batteries negative terminal, that's one helluva clean ground. :) Just make sure the battery in question has a solid ground connection to the frame back there.

tbone - I'd have to guess that you have a weak ground somewhere. You mentioned that you replced/added the various power wires underhood, but you only mention the battery to motor ground. Try adding an additional battery to frame ground, and upgrade the alternators ground strap as well. Then make sure tha amplifier grounds are all up to par. If this doesn't work, we get into the item by item check with a voltmeter....

[DaLazernet]

I guess you could call this a success story? I go to a car audio shop to get all my "stuff" done. My car even has a website for all the mods, etc (although its one install behind - I'll update soon). Well, I have a JL 12W3 pushed by a 600 watt amp and another amp (500 watts perhaps?) powering my Kenwood Excelon Dualmags. I have an excelon headunit, sirius satellite radio and CD changer. I'll often be listening to my stereo from the CD changer or sirius, driving along with my additional fog lights on (so all 4 lights) and my heated seat going without any dim of power - even when stopped. From the posts I've seen on here, I would presume that I'd have about 10 % light output based on all the stuff I have running! Well, who knows. Could some of you folks have the SE, having a smaller alternator which isn't able to keep up to the drain of the systems? Who knows, just thought I'd be a success story...

my website: http://members.sounddomain.com/dalazernet

Check it out, I'd love comments from the GA community :-)

- Eric

[AmIGrand]

Oh don't worry - after it's been in there a while with more hours of hard use, it'll be dimmin'.... :p

[Everclear]

Hey bro i was looking a your future system Diagram. Rear speakers suck unless you are planning on doing a 5.1 or surround sound movie system. Go with the 300/2 and put some more power to the front components and just eliminate the rear speakers they are worthless.

And as far as what you just posted, i woulnt call it a sucess story, cause i have a 300/4 and a 500/1 pushing a 12 W7 and i have No light problems a with low notes or high volumers. and i have an SE

[AmIGrand]

Rear fill is a matter of personal taste, there is no "right" or "wrong" outside the SQ lanes!! ;)

[matts]

that's what i think. i don't see how people can say they're worthless. i can tell a big difference between the rear speakers working and not. i was playing with them the other day and i think i would get used to not having the rear's, but i prefer to have them.

i don't have a light dimming problem in the GA. got 1700 watts rms and even with lights on, blinker on, a/c on, system turned up, windshield wipers going the voltage doesn't move. and it's the stock altenator. but i do have a 2nd battery and a cap :P. but before i had the battery i had 2 different amps hooked up to the 18" and the lights didn't dim. a bd1500 and a 550S, both fosgate. the bd1500 was pushing around 750 and the 550 was almost 600. and the only thing i had added was a 1 farad cap. lights didn't dim with the system up sitting at a stop light.

[Everclear]

Right i would say the only time rear speakers are not worthless is with 5.1 or if you have alot of people in ur back seat. But if you want the best SQ with what you got, eliminate rear fill becuase music dosent come behind you at a concet.

[DaLazernet]

Wow, I'm so happy that people went and looked at my car :-). I suppose I should really update my future system diagram. My original intentions were to go JL for all the speakers, etc, but I fell in love with my Kenwood Excelon Dualmags that I have up front (which sound incredible). The rear speakers are still stock but were put on my new kenwood amp....so basically, I'll update my image later this week to reflect my actual choices, etc. And re: the rear speakers, yes - its true that they are a bit worthless (in my GAGT coupe at least) since I wouldn't subject a passenger to my back seat. Albeit the 5.1 is an interesting idea....not sure if I want to get a screen and DVD going in there just yet. I had thoughts of getting one of those kenwood navigation systems with the screen up front that could also play a movie...but time will tell. I'll update that site and future mods page soon to be correct...sorry, didn't realize how out of date it actually was ;-)...

- Eric

[matts]

but we're not trying to reproduce concert sounds. we're trying to fill a car with as much sound as you can :D. if you still have rear speakers go out and turn the fade all the way to front and turn the car up. then with the volume turned up put the fade 50/50 and tell me you can't hear a difference.

i changed the rear 6x9s in my moms bonneville and can tell a big difference in sound, especially at higher volumes

[matthar924]

I gotta say, I was disturbed by Everclear saying yellow tops are crap. I burned out a Red top in about 2 years and just put in a yellow. Granted, I've been repairing accident damage and haven't really driven the car at all for about 4 months, but the yellow top seems to be at least as good as the Red. At least with the yellow top, Optima offers a warranty if it's being used with upgraded audio components, whereas the Red Top specifically states it is not covered under warranty with additional audio components. I am running a 550.3 Kicker Amp for my rears and sub, and a small ALpine amp for my fronts and had problems with lights dimming, but the red top cleared that up and no troubles from the yellow as of yet. I also have a 160amp alternator sitting at the mechanics shop that will go on for extra help too...I'll have him upgrade the wiring from the Alt to the Battery as well and I should be set.

[cad_99gt316]

ok, well since this thread is kinda old, i hope that someone reads my question! of course my guestion is about why my lights dim. i guess they dim at about 15-30%. what i have in the trunk is a 12" Punch HX2 and a 1200W Boss amp. turned up halfway. i wanna totally elimanate the dimming, but would i really need a 2nd batt.? or upgrade the alt.? i dont have a complex system, just a amp and a sub. please help.

[bubbajim]

A lot of suggestions are already posted in this very thread... but to repeat a suggestion that I know has worked for me in the past.. make sure you use the shortest path possible for ground and use the fattest gauge your amp can handle. The same can be said about the power lines too. The more resistance in your system is not good, so the larger gauge wiring will help reduce the dimming. I have a 600 and 1000 watt amp in my setup and only start to dim when i have the volume cranked to levels that are just too painful to listen too, plus the car would rattle apart if left at that volume. :-)

[DevilDriver]

ok, well since this thread is kinda old, i hope that someone reads my question! of course my guestion is about why my lights dim. i guess they dim at about 15-30%. what i have in the trunk is a 12" Punch HX2 and a 1200W Boss amp. turned up halfway. i wanna totally elimanate the dimming, but would i really need a 2nd batt.? or upgrade the alt.? i dont have a complex system, just a amp and a sub. please help.

you are most likely suffering from a poor battery or you need a higher power alternator. i personally suggest getting a higher power alternator.

as far as the whole "cap or no cap" topic, here goes:

so we've all heard of the case where someone just installed a sub/amp combo that does 500 watts and their headlights and interior lights are dimming when the bass hits. supposedly, the miracle fix is a 1 farad capacitor which suddenly stops this from occurring. i'll start off by saying a little background info about capacitors.

capacitors are constructed by separating two or more conductors called plates with an insulator called a dielectric. if an AC signal is applied to a capacitor's plates, the current will flow through the capacitor. what actually happens is that if an AC signal is applied to the plates, the capacitor will charge one way (hence current flows), then when the AC signal reverses direction the capacitor discharges and then charges in that direction. this makes it appear that the AC current is flowing through the capacitor. a DC voltage connected to the same plates will not pass through the dielectric, and no direct current will flow through. therefore, this capacitor will accomplish a few things: it will block most DC current (accessory noise suppresion), and it will store an electrical charge that can be used later.

now in theory, if your alternator is correctly charging the battery, then the battery will do a much better job of blocking DC current from being sent signal-wise and also produce the required amperage to power your vehicle and your vehicle's sound system. so why is a capacitor used? i personally don't use them except in show situations, however i imagine that in many applications, a capacitor is a more affordable solution than getting a new alternator and battery when you are only having a small power problem. also, it is likely unrealistic that a battery will do a perfect job of filtering DC current.

however, what happens when you are using so much power that you have drained the capacitor? at this point, yes the capacitor is still filtering DC current, but you're also trying to charge the battery and capacitor at the same time. once again, the solution to your problem is an alternator that will power your vehicle correctly.

my point is not that capacitors are useless, but rather that they are being used incorrectly. a capacitor should be used for filtering/blocking of DC current rather than to power your amp when the battery is being drained. and if you are choosing to run a capacitor for power storing purposes, a 1 Farad capacitor is really not a very good solution as all it would take is a couple quick bass hits and your cap would be drained. a 10 Farad capacitor would be a much better answer if you're using one simply for power storing reasons. none of this, of course, takes ESR into accout, but you get the picture.

[MNGT1]

OK One Quick Question to add just to see what people Say. On First off Im Running a Red Top With 4awg running to 2 monster 1fared caps then to 1000watt, 100amp Rockford amp. Running 2 12 type R's. I have 4awg running to my alt from batt, At Idle and at night when running close to 180 watts of lights my lights dim 15-20% just enough to **** me off, I just placed an order for a Mr Alt 160 amp to replace my stocke 105amp.....Do you guys Think will fix the problem???
Thanks

[DevilDriver]

heh, just playing with numbers and here's some fun calculations regarding the recharge rates of capacitors:
time in seconds = (0.5*FARADs*TARGETVOLTS*VOLTSIN)/Power supply in J/s
we'll assume a 100 amp alternator (roughly the equivalent of most stock alternators) at 14.4 V. that's 1440 watts or joules/second

so,
t=(0.5*1Farad*12.6V*14.4V)/1440
t=0.063 seconds to recharge

what if it's a 40 Farad capacitor?
t=(0.5*40Farads*12.6V*14.4V)/1440
t=2.52 seconds to recharge

what if it's a 40 Farad capacitor and your amp and vehicle are already drawing 95 of your 100 amps?
t=(0.5*40Farads*12.6V*14.4V)/72
t=50.4 seconds to recharge

now you get the idea why a capacitor is not so handy....

[AmIGrand]

Perfect, lol. I wish I woulda had those formula a long time ago! It's crude, not accounting for internal resistance and other variables, but it works. Nice work! :)

[DevilDriver]

the funny thing about capacitors is that once there is zero available amperage and your system is at full tilt, the recharge time of a capacitor becomes infinite. the fact is a capacitor cannot truly solve the issue which is a lack of available amperage. a capacitor simply cannot create any form of amperage and the amount that it stores only offers temporary assistance.

one thing i haven't seen mentioned yet is the effects of ESR. in order to remain truly effective, a capacitor should have an ESR rating of 0.001ohms. what perturbs me is that most widely available capacitors have ESR ratings of 0.003 ohms and higher. the higher farad capacitors tend to have consistently worse ESR ratings as well, in some cases as high as 0.04ohms! that's ludicrous.

here are some more fun calculations involving ESR.
ir=v
where i=amperage of system
r=ESR rating of the capacitor
v=voltage drop experienced

100*0.001=.1V :this correlates to 14.3V system
200*0.002=.2V :this correlates to 14.2V system

that's not too bad. let's setp it up a bit to something you're more likely to find.
100*0.003=.3V :this correlates to a 14.1V system
200*0.003=.6V :this correlates to a 13.8V system

now for the drastic example. this is a 40 Farad capacitor with 0.03 ohm ESR rating. this is from a major company that we recently dropped from our sales floor.

100*0.03=3V :this correlates to a 11.4V system
200*0.03=6V :this correlates to a 8.4V system

now you see how ridiculous it's getting. a large capacitor, while having greater storage capabilites, also has substantially larger recharge time as i indicated earlier AND substantial voltage drop due to the large ESR. of course, it's a good example of the lack of knowledge shared by most people within car audio. there are invariably people who don't know the difference between marketing and engineering the same way there are people who don't know the difference between sounds good and sounds loud.

[Metallman56]

punkorama is right about the capacitor. you just cant create power from a cap. however i have a ohio generater alt. the thing is suppost to put out no less then 160 amps at idle and max power is 190 amps. heres the problem. since the g.a. idle is only 650 rpms, the alt isnt spinning fast enough to create much power. i mean less then 12 volts, not alot of power. once you get the rpms up to about 800ish the lights get brighter and i have serious power again. thats one of the things i really dont like about it. one more thing is that when i am really rockin, you know bass that makes it hard to breath, my lights still dim. not as much or nearly as bad, but they still do. i almost never have it that loud though. but if i did it would **** me off.

[Mendoza]

^^^^^^^
You just have to get a diffrent pulley (I think they sent me a ford pulley). I got it free from Ohio Generator shipped with the alternator and i set my idle at 800 rpm's (by adjusting the bolt on the bottom of the throttle body) and my voltages sits at 14.4.

[96GaGT]

my gt normally runs around 800-1k rpm at idle. but it's not the stock engine... it's another 3100 out of a lumina apc van from chevy. so i guess it has a lil bit different tuning for that. besides the extra hp and torque lol. but i still get dim lights when i'm thumping. i can't turn it up really loud.

how do you test capactitors? because i think i might have shorted something or another. i was hooking the capacitor back up when the screwdriver i was using slipped out of my hands and crossed both the +positive and the -negative terminals. almost fusing the screwdriver to it. i immediately got the screwdriver off but the cap didn't work. at least then it didn't ... so i uninstalled the cap.

what i'm wondering... because no fuses blew at all.. i have two on my amp and one on the battery. the cap and amp are grounded to the chasis with 8ga wiring. it's a Lightning Audio la series amp rated at about 600watts rms bridged and at 900watts max. I have it powering 2 pioneer premier 12's 400watts rms each 1000watts max. I know it's not nearly enough for my system and could have been part of the problem.. but it still bumps pretty damn hard... but the problem i am having is that whenever i turn the car on or off the subs pop. not sure how to describe it. but other than that there is nothing else i see or hear wrong with it. oh yea and the capacitor is working again now... not sure if it is working properly or not.. but the digital readout on it lights up now when when that happened it wouldn't. so it seems like everything is working fine... it's just that i have that noise. And if i turn the bass boost +12db on... i can't turn the system up much at all and the popping comes at intervals of different times....

i'm just wondering if my amp and cap are screwed and that i need new ones. i don't really have the money to replace them now. the cap i have is a volfenhag 1.5 farad digital cap that i got off of ebay. from what a friend of mine said they are pretty popular in germany. but i dunno about the company never heard of them before. The amp i got from walmart. it was on the clearence rack for like 60 bucks. now walmart sells it for like 150 bucks. so i figured i made out like a bandit lol. I know don't ever buy electronics from walmart. but the road gear amp that i had powering my one 10 (which is now my computer sub) works really good and still going strong. the subs i got off ebay too.. the guy here was wanting like 115 bucks a piece for the lowest end premier model. i got mine for 77 a piece after shipping. i didn't realise it at the time when i ordered it but i didn't get dvc... i thought i was ordering dvc... oh well... i really want the newer premiers.. that are like 300 bucks a piece... lol that'll be my next upgrade.. these kick arse so i don't see me changing just yet. :P

any ideas as to what the problems might be? everything else is stock.... the wiring from the alternator to the battery and all the ground wiring is stock too. only wiring that is different is the 8ga that runs from the battery to the cap and amp. and the 8ga ground from the amp and cap to the chassis.

[GrandAmGT1996]

Ok, this almost seems to easy...but my question is this how you would have to hook up two batteries in a car. I read through the first page on the How-To type thing, but kinda got it, but kinda didnt. I made an attactchment with the picture, is that how easy it would actually be?

[96GaGT]

it seems that it would be that easy. so yes. you read it correctly. what you are doing is wiring the batteries in a loop. the current flows in a circle correct? (not sure about that one). the battery being used for the amp (second batter) would drain first. then the main battery would charge the second battery. but also while running the car the second battery gets charged. but it's not drawing much current from the alternator because it is already fully charged. it just keeps topping it off every now and then when your not thumping real loud.

no is someone gonna answer my question(s)? :P

[GrandAmGT1996]

I'm really considering a second battery now...does it have to be within (IIRC, I read 18in) 18inches of the other one...or can you run wires to the trunk and have it in there?

Your question, about the popping...my best guess would be possibly your RCAs but I'm not positive. Also, try a bigger ground...maybe 4 gauge.

[Metallman56]

hey mendoza how did a pully set your idle higher? that doesnt make sense.

[AmIGrand]

If his idle has changed - I don't think he said it did - it's because he changed the idle, lol. The problem was that most cars idle at between 800 and 1000 RPM, and the GA idled at 600. The Ohio alt was designed for the higher idle and didn't make enough juice at 600 RPM. The smaller pulley sped up the alt in relation to the engine speed.

Wiring a second battery - if you run them in parallel (your diagram shows a parallel connection, correct) you're essentially doubling the size of the battery. You can mount them wherever you want, just make sure they're secured well, fused, and properly grounded. Batteries can also be wired in series, but that would make a 24 volt system instead of just a bigger 12 volt, and that would be rather bad for the car, lol.

That brand isn't even German, and the only places it's popular are ebay and swapmeets. Not to be rude, just sayin'. The cap is prbably not bad quality 'cuz it's just a capaiter, after all, but I wouldn't look to that (made entirely in Asia) brand for amps or speakers. What's causing the pop.... Could belots of things. First thing, put another known-to-be-good amp in there and see if it goes away. If so, it's the amp. If not, it's something else.

Before adding a capacitor or second battery, first step is ALWAYS upgrade the underhood wiring. The power wire from teh alt to the bat, and ESPECIALLY the battery main ground strap wire. For moderate systems, that's enough to solve minor dimming issues 7 or 8 out of 10 times. ;)

[Luken]

Just wondering, me and my friend have an 02 grand am SE, we have an xplod deck running some alphasonic speakers, 2 12" Clarions with a kicker ZR360(kicker 1200 i think) and ever since we started with the first amp( a ****ty xplod 444 watt) we keep running into problems. as posted before we've had the lights dimming(a Cap is installed, not doing anything most likely) and now recently the fuses keep blowing like theres no tommorow with the new kicker amp, mainly the Main fuse, the wiring is 4 guage everywhere, and everything thing is neat and clean, most things under the good are stock, Alt,Battery, Etc so their apart of the problem too. anyone have any suggestions to deal with this?

[Ajaxus]

can you give a list of all the specific fuses that are blowing? that might help alot more in diagnosing the problem.

[Luken]

its an 80 amp fuse thats on the power line between the battery and the amp, the one right at the battery,
the xplod deck is 4x52 watts,
the amp is a Zr360,
500watts by each sub.
4- guage wiring etc

this fuse keeps blowing everytime we start playing music or start to crank it, even when the amp is only on a quarter gain.
even with the capacitor(1.0QX) installed it doesnt seem to be doing anything.

[AmIGrand]

Sounds like either your power wire is pinched, or your amp is toasted. Could be the sub(s), but the amp should go into protect before popping the fuse. I'm betting a bad output in the amplifier.

[Luken]

could explain "pinched" and expland a bit more on the power wire?

[AmIGrand]

If the power wire is "pinched" under a seat frame or some other spot enough to slice the jacket, it's grounding out. If the setup worked before, that's probably not it.

If the system powers up, but pops the fuse as soon as the amp plays, regarding of volume, it's most likely a blown amplifier.

If it plays OK at lower volume but pops when you get louder, it could be the amp, but is more likely a fried voicecoil on a woofer.

[Mendoza]

Are you using an 80amp barrel fuse? If so i would say thats your problem. Consider the heat the fuse takes in the engine bay plus all the power the kicker amp pulls i would say upgrade to a 200 watt waffer fuse and waffer fuse holder. I used to have a kicker 360 and those amps are little monsters try this out and let me know.
PEACE

[Luken]

thanks everyone, tommorow im going to look into it at further detail so hopefully i can come back with some results with some subtance.

[Luken]

sorry, i also failed to mettion that earlier when it happened the first time, when we popped the trunk to check the sub's there was smoke coming out of the port holes, but they still work quite fine, this im quite stumped about.

[AmIGrand]

What kind of woofers? I've plugged a 15w3 into the wall until the smoke alarms in the room went off, left it playing and smoking for 10 solid minuters, and it wouldn't freeze. It was definately fried, but it wouldn't die! lol

If there was smoke, your subs coils are certainly done, whether it still plays or not. That means they're showing your amp a lower load (if not a short) and it's drawing more power because of it - assuming it hasn't burnt an output! So - there's your fuse problem. Replace the woofers, hopefully the amp isn't gone too. :(

[Luken]

extacly as you said ami, we replaced the woofers with some audiobahns, and now everything is working perfectly, only now is to ajust the gain etc etc thanks everyone for all your help. Oh yeah the dimming has stopped and im pretty sure the capactior is now working,

[bad_jesus]

Ok, this is my first post on this forum, and I am a new GA owner.. maybe I shouldn't start on this forum by posting this, but I had to after reading this thread.

Ok, first of all.. a bit of backround on me... I have been in the car audio industry for about 6 years... I did a bit of installing (I rather suck at it because I get lazy).. I am MECP certified, and I sold car audio equipment for the rest of the time. (For everyone who knows what they are talking about.. yes.. MECP is bull****, and doesn't mean anything.. but for those who don't know what you are talking about.. it means that I do know what I am talking about) :)

There is A LOT of bad information even in this thread that is supposed to be giving clarity. I had to stop reading on page three, so I jumped here.

I am going to explain very simply about diming lights in lamen terms so that everyone understands.. I wont even mention watts, volts, or anything have to do with Ohm's because it really doesn't matter. To a seasoned car pro, what I am saying you can easily pick apart, and say that is not how it works, but realise why I am explaining it like this.. Fundamentaly, this is EXACTLY how it works... for the purpose of explaining it without using any technical terms... this explains it just fine.

Very simply, your lights are diming because something in your electrical system is using more power than it should be, without putting in back into the system, and is making other devices starve. Your cars electricity is basically like a large loop. Every device in your vehicle that uses electricity, takes just as much as it needs, and then spits it back out to the rest of your system.

Think of this like a buffet table. Everyone is eating, and the chefs keep bringing out food. Well, then some big fat kid comes in, and eats all the food, farting real loud just like your stereo is. Well, now everyone else is starving for food, and they are getting weaker.

How do you fix this? Well a cap is def not the answer, just like the first post mentioned in this thread... and for the exact reason that was mentioned...

Do you get a bigger battery and alternator as the next step? No... no you don't.

Most installers out there will tell you I am full of **** right now, because if you do the math, a stock alternator can power your massive stereo.. that may be true.. but for 90% of you that have diming lights, that is not the case. You can go waste money on your new stuff, but that might not even fix the problem, and it is definately not necessary.

If you are running a massive 150-160 db system.. ignore this post.. but if you have an average stereo system... 2 10" Alpine type R's... 2 12" jl 12w3v2's... then I would not jump to the idea you need to replace your battery and alternator right away.

That being said.. of course make sure they are in good working order... if they are ... then try this.

MOST systems will have diming lights because the AMP is using such a large amount of electricity (like the fat kid) but is not dispursing it back in to the system allowing other devices to use it as well. Now this creates 2 problems. The amp can't just, not let electricity pass through it. It needs to dispurse it somewhere. It does so in two ways... of course through the ground, and through heat energy. It is good that is passes it through the ground, it is bad that is keeping it in the amp and dispursing it as heat.

To fix this, check your f'ing wiring. After 6 years of almost daily showing 16 year old kids why they shouldn't install their own stuff, grounds are the most common reason why people have diming lights.

"Well i cleaned the ground spot very good with a wire brush"... thats great.. glad you did that... too bad your ground is 20 feet long and 8 gauge... or.. too bad your gounding it to tin flasing that is glued on to the inside of your trunk...

There is no definate answer to where is the best place to ground your stereo. Every system is different, and every car is different. I can almost guarantee you though, that it is the reason for your diming.

My most common answers when asked why lights were diming was

1. Check your ground, make sure it is clean, tight, not open to the elements, and attached to a major groundable support structure. I have even noticed that adding a grounding strap between certain panels in the vehicle hace stopped lights from diming.

2. Check your power, and ground. Make sure that your power wire can handle your needs, and if it is barely handling what you need, step up the ground, or shorten it if you can. There is no problem is running an 8 gauge power, and a 4 gauge ground. Some installers say this will cause noise, and sometimes it can... however, that is rare, and if causes noise, then try something else.. but if it stops your diming without causing noise.. guess what... you are a genious.

3. Don't be stupid.. if you are running a 400w amp on a JL 13w7... you obviously have the damn thing cranked and it isnt working to its potential, and is causing a lot of problems. Run things how they are supposed to be ran. If you can't afford to run it properly, then don't buy it. GAIN IS NOT A VOLUME CONTROL!!!! lol.. I can not stress that enough.. I wont bother explaining what gain actually is, but it IS NOT VOLUME!!! yes i realise it makes things louder when you turn it up, but it also adds that distortion that loves to heat up voice coils and turn your ports into fog machines.

If all of that fails, then.. and only then.. look in to beefing up the cables on your alternator. This rarely does anything, but has worked in the past.. If that still fails then get a new alternator/battery.. or add another battery.. or whatever. If you add another batter, make sure you do it properly and use a kit / relay system. Don't just run it in series, or parallel like I think someone was mentioning early.. that is retarded.

If all of that fails... TURN IT DOWN!!!

Now welcome me to the forum :)

[normal]

Im gonna go ahead and be the first to disagree with some of what you are saying... I don't know the SPL my system pushed but i know it isn't 150-160, i have two amps, one for my coaxials and one for my subs. The coax is a RF P2002, the other amp is a kenwood KAC 9102 which is rated at 850 W RMS per channel the way i have it wired. The subs are a pair of Power Acoustik FUBAR 12's, rated at 900 W RMS each. My power and ground are Stinger 1/0 gauge with patinum terminals, grounded to the chassis. With all of this, when i first got it all installed i had no dimming whatsoever, and i could blast it in teh parking lot. After about 2 weeks of doing that i started noticing a lot of whining coming through the speakers, so i spent some time trying to figure out why since i had rerun all wire very carefully, and hadn't had the problem until then. not being able to figure anything out, i sat in my car (car on of course) and started messing with the head unit etc. after a short while i started noticing my lights would dim quite a bit, which had yet to occur. leaving the volume up, they got worse and worse, and then the subs would cut off for a second or two then come back on, you would say that i had the gain set too loud or such, but i set them with a voltmeter very carefully with a 50 hz track recorded at 0 db. it wasn't until my head unit cut off for a split second that i realized what was happening. what you said about the closed system is true, and i agree with you. however it is a little more in depth than what you campared it to, the battery supplies the power. the alternator recharges the battery. in normal use the battery doesn't use a significant amount of the charge stored, so the alternator can charge the battery as fast as is discharges. when you begin adding in subs, amps, and other goodies, you start pulling more charge from the battery. the problems begin when you pull charge faster than the alternator can add, thus you begin to drain the battery. adding a higher output alternator (which can charge the battery faster) will certainly help, and adding a second battery to the system can too, however, if the second battery gets drained then both are just added resistances in the system and puts even more load of the alternator. so in your analogy a second battery is like adding another chef so they can bring more food, however, unless there are enough ovens to cook the food, the chefs can end up standing around...

[bad_jesus]

Well I don't really think you were disagreeing with me there, rather just continuing on from what I said.

Keep in mind, like I mentioned in the beginning, I was dumbing everything down a bit. And yes, there are loopholes in my analogy... but the base of what I am saying is the same as you.

When I mentioned the 150-160 db range, I was not being very exact. If you have ever heard 150 db, that is a pretty extreme stereo... not to mnetion 160...

Like I also said.. every system and every vehicle is different, and there is never a cut and dry reason why your lights are diming.

However, I could still argue with you.. because it is very rare that someones system is drawing that much, that the battery is no longer charging. Yes, a lot of systems, ie... yours... will do this, but it is not common. The reason is because U would have to be POUNDING yoru system more than not when the vehicle is running. The majority of the public with stereo's believe it or not, does not pound their system the entire time their car is driving. In fact, in my 6 years in the industry, I can only think of one specific time that a kid had that problem.

Also, the 9102 is a pretty hungry amp.. remember that it is meant to be strapped, not ran alone. or am i thinking of the 9152... bah well.. one of the two...

Just remember, how vague, and non specific I was being in my little rant :)

[Metallman56]

i dim my lights with my subs, but only when i really really have it up loud. i have a pair of Boston Acoustic 12" G5s with a Boston GT-28 powering them. i have 2 4 gauge going into the + of the amp, and 2 1.5' 4 gauge grounded to the chassie. i have a optima red top and a ohio generater alternator, that is rated up to 190 amps. the boston amp is pushing out 450x2. not THAT much power. less then 1000 watts. i can still dim them like crazy. i dont know why. i also have a kicker 100x2 for the boston SL95s out back, and a Kenwood 25th Anniversary XXV-02A 4 channel amp for the Boston z6s in the front. which puts out 124x4. i dont get why i'm still dimming the lights. oh i also can drag my voltage down low enough to blow the fuses in my amp cause it cant get enough power. which if my Pioneer N2 volt meter is right, is about 11 volts flat. give or take 0.3 volts either way. 4 25 amp fuses. any help with this would be great. i have no clue.

[AmIGrand]

Double check all the wiring and connections, and REALLY pay attention to the ground wires and locations. If the OG is really putting out 190 (probably less at idle, though) and you have a redtop, you shouldn't have issues. Also, what resistance are the voicecoils on those woofers, and how are they wired with the amp? If it's running under it's rated load, it'll be drawing more current than it should.

[Metallman56]

both ground wires are not on paint within a few inchs of each other.

thats what i thought

there 2 ohms. the nice thing about boston is that you dont have to d*ck around with the voice coils. you can either run the woofer at 2 ohms for 8. there are 2 fuses on the woofer. if you want 2 ohms keep both in. but if you want 8 ohms, then take one out. here the manual to the subs. i have the 12-44, the DVC's.

http://bostonacoustics.com/manuals/G5_GTR_Man.pdf

heres how i have the subs wired to the amp. this link is of the amps manual. you have to scroll down quite a ways before you get to what you need to look at. your looking for example C. that is how i have them wired.

http://bostonacoustics.com/manuals/GT28_24Man.pdf

if you see anything i did wrong, or have any questions, let me know. and thanks for the help bud :cheers:

[AmIGrand]

Soooo - you have them set for 2 ohms, and you wired them like example C?

If that is correct, you are running your amp mono into a 1 ohm nominal load. And that handily explains why it's acting like it is. Leave them wired to the amp like "C", but switch the connections on the woofers for 8 ohms. You'll be runnin mono into a 4 ohm load, making 900 watts. Believe me, you won't notice the tiny dip in power (the amps power supply is cutting way back anyway right now, you're probably making LESS than 900, not the 1350 they claim for mono 2 ohm operation), and 450 watts split between two woofers at peak power when they're already seeing over 400 each won't make an audible difference. Your amp will run much cooler, your lights won't dim much if at all, the bass will be cleaner and punchier, and you won't blow any fuses.

;):tup:

[Metallman56]

hmmm. . . what if i wired them like example B? would that fix it? the only reason i ask is cause i've damn near stripped the holes on one of the woofers from pulling it out so much. i think its on its last leg, so i'd rather not pull the sub out, if thats possible.

[AmIGrand]

Are they in a common-chamber in the box, or seperate chambers? If they're in a common chamber, I wouldn't recommend anything other than what I said. If they're in seperate chambers and have seperate connections on the box, you can wire them in series outside the box. Simply disconnect the + from one side and the - from the other (doesn't matter which is which), so you only have two wires running to the amp, a + from one speaker and a - from the other. Then cut a short length of wire and connect the now empty + from one side to the now empty - on the other. You should now have a + wire from the amp to one woofer, a - wire from the amp to the other woofer, and a 3rd wire connecting the other + and - terminals on the box. Voila' - 4 ohm load, amp satys bridged, everything's happy.

[Metallman56]

i did what you said, and it works great. no more dimming. now i get to see just how loud my subs are. thanks for all the help.

[AmIGrand]

That's why we're here, man - you are most welcome. Enjoy! :)

[DoCDooM]

Hello all,

This is a back to basics rant for anyone who is interested.

Maybe this is a dumb question but when you installed the capacitor did it come with a safety drain resistor connected across the terminals and if so, ... did you remove the resistor?

That resistor can put a significant load on your electrics and is supposed to be removed once everything is hooked up, BEFORE you turn the sound equipment on.

Have you cleaned your battery posts (screw jacks sorry) and connectors lately?

I recently replaced both my positive and negative battery cables, they looked OK until I removed them and found corrosion at the engine block and fuse block ends, the battery end connectors "seemed" OK as well until I saw that the lead was starting to look dark, (the old battery was sulfating like and old Ford)

Changed the battery a week before the cables, BIG improvement when the cables were replaced.

North American cars built in the last 15 years or so have been notorious for bad grounding issues, "Ground Loops" occur when the electrical resistance varies between the negative battery post and the engine block, the frame in multiple places and anywhere that you might expect to connect your amp's ground wire to on the body.

I've seen as much as a 1.5 volts drop between the battery and the floor of the trunk in a modern American made car, (to be fair the imports are only marginally better these days)

This problem is caused by the relatively low grade metals used in the body, the lack of an end to end steel frame and the tendency of many manufacturers to use wire and cable in the factory harnesses that is just barely a large enough gauge to handle the current running through it under normal circumstances.

Tis they way of the world I'm afraid and nothing will be done to correct these issues by the manufacturers.

I've found that running some nice welding cable (Ought 2 is nice and heavy) from the battery to the back of the car and connecting it to the body as a supplemental ground has worked very well.


CHeers from the old Electronics guy.

Dan