My battery light stays on.......???? [Archive] - Forum


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03-15-2009, 02:54 PM
My battery light is on. I have replaced the battery and the altenater. What else can be wrong?? After replacing both the light remains.

Ima at a loss since my voltage regulater, according to the haynes manual, is internal on the altenater.

03-15-2009, 04:11 PM
8 views and no

Before new alt

eng off:

batt 12v
alt 12.5v

eng running:

batt 12.5
alt 12v

After new altenater install:

eng off:

batt 12.3v
alt 12.11v

eng running:

batt 11.66v
alt 11.62v

03-15-2009, 04:24 PM
Thats odd for the volts to drop after the new alternator while the engine is running. I don't know if this is correct but you did hook the wires up properly right?

03-15-2009, 04:56 PM
there is only one way to hook up the wires.

03-15-2009, 04:58 PM
should be around 14.5v engine running IIRC.

Are there any other components that come into play as far as the charging system is concerned??

03-15-2009, 05:00 PM
Cut the boots off the cables at the battery. It is quite common for the wires held inside to turn into powder from corrosion. This puts extra strain on the charging system and can cause the alternator to go bad from putting out power to a battery that cant accept it due to corrosion.

03-15-2009, 05:19 PM
Hmmm when I yanked the old battery there was some corrosion around where the battery was. Ima going out to have a look when the wife gets home at the condition of the cables.

Stay tuned, we're not finished here yet..........:slim

03-15-2009, 05:56 PM
replace both the positive and negative cables its cheap and just a good thing to do after a while, and also check all your grounds and make sure they are tight and free of any corrosion.

03-15-2009, 09:53 PM
check the cables by looks and then for resistance with an ohm meter... not sure what the resistance should be, but if its a lot, then cables....

also, i've got a new alternator(and various other parts) before that were faulty in new condition, so that could also be it, hey these are made by us humans.... a parts store should be able to test if its working properly or not....

03-16-2009, 09:32 AM
The alternator is tied to the rest of the electrical system through a fusable link. Yours might be blown.

03-16-2009, 10:09 AM
If the fusable link was open, he might not see 12 volts at the alternator. I think he has another bad alternator - take it to and Advanced Auto or Autozone and have it bench tested.

03-16-2009, 05:45 PM
wipers wipe slow window barely goes up and the hvac blower is barely blowing.

03-16-2009, 06:45 PM
nevermind. It's fixed:crazy: Ima idiot.

03-16-2009, 06:59 PM
What did you do?

03-16-2009, 08:02 PM
connected a plug into the altenater:applause:

03-30-2009, 07:08 PM
How do I post a question on here??????All i see is post reply,.where do I post at????????

03-30-2009, 07:11 PM
GM alternators are known for going out very early in the vehicles life,to early. If I had a problem of a new alternator not charging i would check the voltage at the output wire of the alternator with vehicle running, if not charging between 13.3-14.5 volts I would assume its a bad alternator.

03-30-2009, 09:37 PM
How do I post a question on here??????All i see is post reply,.where do I post at????????

Hit the "New Thread" button at the top of the section you want to post in.