Hey guys,

This one really has me stumped, I have an 86 Camaro and the Alternator went bad, so I replaced it with another Alt from Autozone then quickly realized the old Alt took out my battery so I replaced that as well. That was nearly a month ago, since then I've gone through 3 additional Alternators all showing similar issues, with no accessories on I run SOMETIMES near 13v, if I turn my headlights on that'll quickly start dropping me and when my cooling fan is on it brings me down even further. However, I can take the positive terminal and disconnect it and the car will continue to run, moreover the voltage will shoot up to 14.6v UNTIL I reconnect the battery.

The battery is new and has been load tested and fully charged and this issue will continue to happen and this problem spans over multiple alternators. I figured it might be a wiring issue or ground issue but can't find one. Lead from the Alt to the battery is good, I assume that the lead from the battery to the starter is good as it starts right up and all the grounds seem in good shape. Does anyone have ANY more ideas of what this could be? I'm completely stumped.

 

Just an update, I found this link "Check Your Relays", and found this to be one of my issues, however I no longer have an electric fuel pump. Tying off the wires did allow my voltage to come up to 13.

I jumped the field wire from my alternator to the battery which brought my voltage up to 14.5 with no load, and just over 13 with load. I then drove the car around for maybe an hour in town and my gauge stayed pinned at 13v with no load and it would come down slightly under load. When I returned to my house I put my multimeter on it and saw it hanging at 12.97 with no load and with everything on around 12.1v, still not great. I'll keep searching but if anyone has ANY input I would greatly appreciate it.

Thanks again!

 

had kinda the same thing, 3 altenators from auto zone.. my Volts would drop below 13.. with a load.. amp, headlights. I think I finally got it fixed. The alienator belt used to raise cain. an I would notice a volt drop. Ive replaced the crank pully, waterpump.. w/ pully.. an got a new belt.. picked up a new battery today,, combo of possible problems. belts, and failing parts.. got the lifetime warranty 2.,..

 

I actually took the car out a little while ago and noticed the belt is slipping quite a bit so that's the first thing I'm gonna change tomorrow while having the alternator and battery tested at Autozone although I suspect they'll pass. I've run though everything I can think of, what I can't pinpoint is why the voltage drops so much when the battery is connected.

Car running w/ no load: 13.2v
Car running w/ load: 12.2v
Car running w/ no load and battery disconnected: 14.6v

That's the real kicker. :/

 

Thanks! Turns out it was a bad ground and a bad belt!