OK, I'm gonna freakin' lose it and blow up my Camaro.

Awhile back I noticed some voltage problems: the voltage would drop from "normal" of 15 or 16 volts down to 12 or less once the motor warmed up. Well, after "fixing" it I made the damn thing worse somehow!!

Here's what I tried and the order that I tried it in.

1. New Battery
2. New Alternator
3. Replaced voltage regulator plug (exposed wire)
4. Replaced positive battery cable (exposed wire, corrosion)

None of that has worked, and now the system does not recharge the battery at all. From the moment I start the car I get a constant 12 or less volts. I have tried both the new battery and alternator as well as the old components: no change.


Anybody have ideas, besides a block of C4?

 

1st question before we go any further:

Are you basing this off the factory dash volt meter?

 

Yes, but the cabin lights also dim and the Choke light comes on when the volts drop, so it seems to be more than the meter.

 

Damn dude, you must have the same gremlins who live in my transmission. I know your frustration. Take a day or two off, sometimes thats all I can do to stop me from putting a flaming rag down the gas cap! Good luck!

 

glue the needle in the gauge to read 14 volts....then charge the battery up real well.....then drive it straight to the dealer and trade her in....lol...
now really....use a voltmeter and check the positive wire off the alternator....it goes to a lug on a plastic bracket near the battery....make sure the connections there are good(no loose wires/corosion) also, sometimes these gm alternators are defective from the get-go....I worked at autozone for 5 years....once a month...I pulled a bad gm type alternator straight off the shelf......just make sure the hot wire off the alternator is hooked to the battery.....the regulator is internal....and feel if the wire is hot(temp wise) it could be breaking down and the amp draw is desenigrating the wire

 

Don't rely on the dash meter. Go get a volt/ohm meter and read the voltage at the bat. My guage reads almost in the read when my car warms up but with a meter on the battery it reads 12.5 volts. Make sure your grounds are good. Check to make sure the voltage goes up when you rev up. If it doesn't you got a bad alternator or voltage sense wire.

 

If you have the electric choke it could be shorting out. This is a fairly common problem. Choke has a coil and a relay. Need to check both.

 

Alright gang. When the rain clears out of here tomorrow, I'll put the meter to her and check it out.

Z28SORR: How would I determine a short at the choke? When I first started having the problem (exhibited as a drain only when the motor heated up) I pulled the wires off of the choke (pos and neg). Well, then I still had the drain but the choke light didn't come on.

 

check all the grounds and the choke. i wouldnt know how to check the choke but i imagine you could just unplug it crank her up and see if it helps

 

A loose or corroded ground can cause the same problems.

 

Also, if your engine starts to run hot it'll heat soak the Altenator and it wont charge at its full potential. That could have been your original problem and when you replaced it you got a bad altenator. Thats what mine does.

 

OK, put the voltmeter to it. With the motor running...

Volts at the alternator were 12.38

Volts at the battery were 12.38



Am I back to looking at the alternator? I'm so damned confused now. Like I said, the old alternator gave the same results (on the dash gauge) as the new alternator, but had bench tested OK.

 

So I've been thinking on it for a few hours: if the voltage coming off of the alt is "low" (12v versus the expected 15v) then the alt would be bad, right? Not that there is a short somewhere else in the system, because if that was the case then the alt output would be normal (~15v) while the battery would only readout at ~12v.... right?

 

I can't wait to see what is wrong. I have a similar problem. I had my car painted a few years ago, and the guy replaced almost all the body panels because of rust, and coincidently I had the same problem with my charging system. Which I would think would be the whole grounding idea, BUT ... my computer was disconnected up until that time frame which cause my choke light to stay on ... and maybe it was disconnected by the previous owner to stop the choke from draining my battery ... which could be the same problem you have ... just thinking out loud. Whew, that was a lot.

 

As I have looked at the different grounds in the car, I'm wondering how many there are and where to find each?

So far I have looked at the negative battery cable ground to the quarter panel, the negative battery cable ground to the engine blick, and the electric choke ground to the carb. What else would I look for?