Background, I have two C6's. An '08 Z06 that was bought new as an autocross car and an '06 Coupe bought used as a DD.

Last weekend, without warning on the first lap, the stock alternator got fried. Pulling back into the pits, the alternator was smoking like crazy. It felt like it was going to catch on fire, so we poured water on it and the smoke eventually faded.

Drove to auto parts store(s). No alternators to be bought. Drove home, took alternator out of DD and installed in the Z at the track. Drove 25 miles around town and everything was fine. Took a total of 3 more laps, and that alternator is now fried too. Not smoking, but when put back into the DD, it too seems to have fried the voltage regulator.

Fast forward to this weekend. Checked all grounds, don't see anything loose. Installed brand new alternator, turned car on no problem. It initially registers about 14.5 volts (normal), but about 10 seconds later, it pegs MAX VOLTS on the dial and the computer starts to freak out.

If I disconnect (which I did) the wire harness, the car starts and drives perfectly normal. Also indicating the 11.7 volts by default that my DD did when I returned it's alternator to it.

I've since put a brand new alternator in the DD, and it's back to being perfect. The Z06 is hosed.

My best guess is that the (rather substantial) wiring harness for the alternator, intake, coils, ... (they all appear to be the same thing) may be toast. That being said, when alternator 2 went in, the car drove fine for a very long time at "normal" rpms. I've read on this site that something else comes into play at high rpms.

FWIW, Battery is also 100% new from last weekend and is fully charged.

TIA for any advice.

Craig

 

WAG on my part: something in the computer is causing the alternator to go into overdrive, so to speak.