I'm having some very bizarre charging problems. I have a 92 Z28 with the 5.0 TPI. When I start the car sometimes the battery gauge is just at the first line witch i think is about 10 volts, and other times it is straight up at 13. Doesn’t matter what the rpm's are. When driving it will sometimes bounce around from bellow the first line to just about pegged on the gauge I have replaced 6 alternators in 5 years cleaned all ground wires checked all the connection and nothing helps. Has anyone else had a problem like this?

 

Have you considered the voltage gauge being bad.

 

yep checked that. I had each alternator checked before I replaced to make sure it is dead.

 

What brand alternator are you using, what rating is it, and do you have anything on the car like a BFS that would cause a power drain. Also, have you changed your battery as well or had it checked.

 

Presently I'm using a BOSCH 120 amp alternator. I replaced the battery twice. This latest alternator so far has lasted the longest. Since it doesn't happen all the time i'm having a hard time finding the problem