I own a 1987 Camaro equipped with a 5.0 TPI and TH700R4 transmission. My issue is that during normal operation, not using the air conditioning system the voltage is normal. When I turn on the air conditioning system the voltage drops, but the real issue begins as change the stages of the blower motor. As i go from low to medium to high, during each stage, the voltage is dropping until finally it gets below normal.

In an effort to correct the issue, I replaced the old alternator with a new 105 amp alternator.

At night when the lights are on with the air conditioning system running, the voltage is extremely low that the lights dim and the signal lights barley flash. From what i understand, a low voltage system will damage the fuel pump and eventually destroy it.

Has anyone had and resolved this issue? Any help is greatly appreciated.

James

 

Check the engine to body ground strap and if that is intact,start looking for bad connections elsewhere-feel for connections that heat up.'87s are very easy to upgrade from cs130 alternator to far superior cs144

 

Thanks! Ill check into that.

 

Engine ground strap is tight and the problem persists. I noticed that when i apply the brake the voltage needle jumps and then returns to normal. Also when a signal light is flashing, the voltage needle is jumping along when it turns on and off. Any ideas?

 

 

Thanks for the response NINA!

With the engine off and COLD, the voltmeter displayed 12.34 volts.
Engine running, the voltmeter displayed 14.74 volts.
Once the engine was hot, the voltmeter displayed 14.20 volts.
With the engine hot, running and headlights, fog lights, radio and A/C turned on, the voltmeter displayed 14.10 volts.
When I put the car in drive, with the engine hot, running and headlights, fog lights, radio and A/C turned on, the voltmeter display drops to 13.24 volts.
If i apply the brakes, the voltage drops even more.

Currently, the car idles at 10,000 rpm and in drive idles at approximately 400 rpm. I can't set the idle any lower because as soon as the car is driven, the idle in drive will drop to an extremely low rpm... I don't have any codes, I have fixed the one it was flashing which turned out to be a vacuum leak; I don't get it but this nonsense is really ticking me off!

Thanks again,

James

 

Alternators need speed to produce current. Raise idle speed in gear and everything will probably be fine.

You probably need to work on idle settings in general. There is something wrong when idle speed changes so much in gear versus neutral.

 

Why would the voltage needle drop or bounce every time I apply brakes? The voltage needle also jumps in rhythm with the turn signal.