VERY Strange: Head Unit Dimming With Blinker

[Rba007]

Alright, installed MSD+new spark plugs yesterday. Today, I find that when my blinker is on, my JVC KDSH99 Headunit is dimming with the blinker. Any ideas?

(Also, I realize I also posted this in the tech section. But, I know since I rarely ever get into this section, some may not often visit the tech section... And I know you experts here will come up with something).

THANKS!


-Dave

[MattBatt]

That's MSD as in Multi Spark Distribution Right not some name brand. My guess is that the blinker is on the same circut as the HU and so the voltage drop is affecting that circut. Have you tried doing a search for other people with MSD's and see if they had to upgrade their alternators and or batteries.

[SC/TGrandAm]

yes definately sounds like your pulling almost all the power that you have when you turn the blinkers on. Are you by chance running a stock battery Dave? Its probably those darn HID's hah j/k.

Im going to step out on a line and say your battery is going shot, you can go to autozone, walmart, etc and have it tested for free(along with your alternator) then you will know. Do that first and then go from there.

[Rba007]

Thanks for the replies guys.

Ive got an nice optima red-top that is running fine, along with a 160 amp alternator already. And, I can run my headlights on high beam, then my foglights, and my extra set of 55 watt driving lights plus my defroster and not have any problems. Stupid thing just blinks when my blinker is on...

MSD as in, the nice Red ignition systems...

[matts]

i've got a 180 amp altenator on my truck, but i can still watch the voltage gauge move, not much.....but it still moves, when the blinkers blink. especially when i've got any other kind of load on it. is it almost going dead or is it just dimming a little?

[Rba007]

Just dimming like it dims when my headlights turn on. When the headlights are on, it doesnt dim. So, something is making it think that my headlights are turning on and off when my blinker is going. Stupid Machine.

[matts]

i really don't think it has anything to do with the actual radio. sounds to me like there's a wire crossed somewhere for the car and it's just filtering down to the radio and that's where you're noticing it.

[quinton]

yeah, id say your DIM wire is messed up somewhere, if it were me, id just unhook the dim wire as it is optional. of course your hu wont dim when you turn you lights on anymore.

[matts]

you could do that or you could run you a whole new dimmer wire. just tap into your parking light wire and run it from over there to your stereo dimmer wire. in theory that SHOULD take care of it......but it may not :P

[MattBatt]

Jeez I'm like 0-15 on solving problems lately

[fschambe]

here's a thought... did you change ANY bulbs for your turn signals? Does it blink only one signal or either, does it change with hazard lights? Turn on your parking lights, radio dims, what happens when turn signals are now activated, no more dimming then regular dim? What I am thinking is that one of your bulbs are in wrong and it is causing the voltage from the turn signal circuit to leak into the parking lamp circuit which is what activates your HU dimming. The HU looks for much lower than 12V sometimes, incase you wired it to the dimming circuit for the dash lights which can be as low as like 3v when they're dimmed. Try this for more trouble shooting, turn on your parking lamps and set your dash dimmer all the way down and see if when the turn signal is on the dash gets brighter or not.

[Rba007]

Hmmmm, havent changed any of the bulbs in the last year or so, and this just started. But, to answer your questions:

When headlights are on, and blinker is used, it doesnt dim, but the blinkers go crazy fast like one of them is out (they arent).


Dont know about the hazzards though, I will check shortly. Thanks for the ideas everyone.

How would I go about un-attaching this dimmer wire? I had a local installer throw my HU in ( only ran 20 bucks, so i went for it). Thanks!!!!!

[fschambe]

see if they used a wiring harness for the HU, if they did there's more flexibility for experimenting without having to cut your cars factory wiring. Have you seen your blinkers working (all around car exterior) when your headlamps are on? It is remotely possible that your affected by the turn signal switch recall which is in the works, IE, solder joint cracks causing random shorts. Because it sounds like your parking light and your turn signal circuits are linked together somehow.

[MattBatt]

By the way there are two blinker bulbs in each tail light assembly (that's what threw me for a loop)
And dont' forget to check that you blinker fluid isn't too low

[Rba007]

Damn, my muffler bearings went Bad!!!!!



It would seem that one of the filaments in my front 3157 bulb went out. The right turn signal works, and does not dim the HU. The driver's side works, but dims the HU. Also, it does not work at all when the headlights are on (the driver's turn signal). My guess, would be that the dim filament is all that works. When it is already on with the headlamps, it turns off when i turn on the blinker.

SO, because its the "parking light" filament that is working, when the bulb lights, the car thinks that my parking lights are coming on, which dims my HU. Make sense?


It doesnt turn on any other interior light though...

[MattBatt]

OK i'll take your word for it. it's an easy fix right.

[matts]

i didn't even think of the actual bulb causing that . in my truck when i have a blinker go out it just flashes really fast. so i get a new one and change it. go figure. all this new fangled stuff.

and i've had my muffler bearings go bad before. very costly repair. . my truck was in the shop for 2 months. they had to special order the parts from greenland. and the eskimos were on strike..........it was frustrating

[matts]

Originally posted by MattBatt
OK i'll take your word for it. it's an easy fix right.

he's gotta replace a blinker bulb

[MattBatt]

I'll have to remember to check my muffler bearings That's great

[Rba007]

Just noticed today that not only does the HU dim, but so does my odometer.... And, when ive got the hazard's on, the front 3157's dont light at ALL. Neither one of em...