Ok, According to the stock pos voltage gauge on my 86, at idle with headlights on Im only getting somewhere between 11 and 11.5 volts. At load the car gets just over 12, couldnt be more then 12.5 volts. I cant get exact voltage since i let someone borrow my multimeter and cannot remember who (dont you love it when that happens). What do you guys think, Faulty altenator, Bad ground somewhere. I swapped the battery already and its not doing much better then the last one. Without the lights on I can drive the car fine, but at night I have to heel toe every stop light to keep the revs up. So what do you guys think. Once again its a 86 GXL.

Statik

 

Try adding more ground cables in
there's a write-up on this somewhere, can't remember where
And run new line to alternator from batt

 

Here it is:
http://home.rmci.net/panther/Low_Volt.htm

 

You have to heel-toe to keep the revs from dropping at idle? That is a problem with your BAC valve, not your battery or charging circuit.

Your voltage sounds pretty normal to me. FC alternators are just not that great.

 

Make certain alt. belt is TIGHT! There should be minimal deflection.

 

Thanks, Ill try that this weekend.

Statik

 

I was being a little sarcastic, The revs fall to normal idle. I just have to rev to at least 2K to keep the voltage gauge at 12 volts, Anything under 2K for two long with the headlights on and the car may not start up next time.

Statik

 

Definitly an alternator problem then.