The car is a 2002 LS1 Camaro

After installing a new set of Spec D tuning ebay headlight to replaced my broken factory ones, I was aiming the headlights on the car with the engine off and boom after about 30 minutes the car is completely dead in an instant - to the point not even the interior lights flip on...ok that's maybe to be expected seeing as the car wasn't running.

I boost the car and the battery cables smoke a little bit and get hot as hell...weird??...car starts and ends up dying at idle about 5-10 minutes later...no biggie, pull it in the driveway and put the trickle cell charger on it. Battery goes from "dead" and zero response from electronics to showing 100% charged in about 10 minutes...weird but whatever ok... cars sits for 2 weeks and still fires up without issue...however, when driving the volts seem to be dropping into the red area of the gauges.

Sooo.. I grab the voltmeter and I verify after letting the car sit over night - battery shows 12.4 volts across the terminals.

Key on engine running it was showing 13.1-13.3 volts...so I believe the alternator to be junk. Call the scrap yard and pick up a truck alternator as a replacement and pop that in... start the car up and it shows 13.8 volts...after a drive and a retest it shows 13.1-13.3 volts at idle...if you rev the car in neutral I drop to about 11.xx volts above 3,500 rpm. If I enter the highway and go WOT by the time I hit 80mph my check gauges light is on and I am buried in the red on the volt gauge.

So I think maybe it is the exciter wire?- I pull that plug off this morning and I got 9.78 volts going to that plug with the engine running and it unplugged from the alternator.

So I am stumped...battery shows good, exciter wire I think is good, they tested the alternator and said it was good? What the heck could be wrong?

 

is there anything else I can test?

 

So I pulled off all the grounds I could find, sanded them down, cleaned them up. I pulled out the ground strap from behind the alternator and it was full of green corrosion. I replaced it with some spare 4gauge wire I had lying around.

Fire the car up and I get 14.xx volts on cold start- great I think it’s fixed... go to back out of the driveway and I can see the volts dropping... go for a drive and anytime I am above 2500 rpm the voltage is in the red. If I put the selector in 2nd gear and drive above 2500rpm for 5-10 seconds my check gauges light will come in due to low voltage.

I am stumped- is it back to being the alternator? Is there another way to test things?

 

Sounds like the alternator to me...

 

Is there any possible way I do some tests to know for certain before I shell out for a rebuild of the junkyard truck alternator? There has to be some more tests?

 

Couldn't hurt to pull the alt and take it to an oreillys and have them test it.

typically if you're seeing smoke and wired are getting hot you have a short somewhere. either wires were backwards or something was touching something it shouldn't.

hopefully you didn't fry anything when that happened.

 

The junkyard had tested it as good- and it appears to work well on cold start up and idle- it seems above 2500rpm (load) when it has issues- so is there a way to isolate and be sure it is the alternator failing under load and not another issue?

as for wires getting hot- that only happened during the jump start- but all jump wires were connected properly without touching anything it shouldn’t- so that’s also a mystery

 

get rid of that battery.

check all of your major electrical connections--positive to alt, starter, and fuseblock, all major ground, as well as the battery terminals.

check the fusible link on your car.

 

That's the alternator. I've had at least 10 that would work fine right after I started the car and then they went to **** as I drove. You probably got a truck one that had been replaced and wasn't an original OEM GM alternator. Try another one.

They act up after running for a while and heat builds up. When they are cool they perform fine. When they test them on the bench they are cool and act right. I went through this a million times. Would go to **** on the car, I'd go to return it, they would test it and it would be fine.

I created the truck alternator thread because of this crap. I wish you were in texas I have an original OEM alternator I would let you try to confirm it's the alternator.


I have a battery charger at work that the ends smoke on if you set it above 10 amps, these days things are coming with garbage wires and clamps that have high resistance. That may be what you had going on with yours.