I believe the other gauges going wacky is a symptom of the root problem.....overvoltage.

I just got back from Napa, they said that the high voltage regulator in my current one was bad, but didn't do the leap to 18 for him. I was talking with the guy behind the counter, and he said that my gauges would go haywire when the volts jumped that high, and he said I was lucky every bulb in the car didn't burn out at once, like his buddy'* did. He also said that this was an unusual way for a GM one to go, more common in Fords.

One last warning he gave me was that maybe the harness has bad contact, and it'* burning out the voltage regulator, so to watch for that if I toast another alt. I'll be putting this one in soon, and taking it for a drive, so I'll keep everyone posted.

Well it seems to be working at the moment. I put the new one in, drove it around with defog and headlights on, and the gauge is hovering just below 14. It'* not that wet out at the moment, so I may take it out when there'* a lot of spray and see if it works consistently.

I'm hoping that this was a simple bad alt from Napa, and that it'* fixed now. I'm not so good at electronics, but if I plug it in and it works, I'm happy. This one didn't cost me a penny, either.

93 does this