n8dogg

This one has me a bit confused, maybe someone can help me out.

2006 Corvette, A6, 20k mi, had the alternator rebuilt due to no output from it originally.

I put in the rebuilt alternator and road tested the car. Idle and normal driving everything seemed OK, voltage reads 13.3 to 14.3 volts (Alternator has output). Under WOT the alternator almost immediately fails, voltage drops to battery voltage and "Service Charging System" message on. After letting the car sit overnight, the alternator has a hard failure and engine ran off battery voltage.

I took the alternator back to the electric repair shop, they went through it and said the voltage regulator took a dump. Replaced it free of charge. I installed the alternator in the car and tried it out again. Same thing, normal driving it had output, as soon as you went WOT it failed hard.

So either there is something wrong with the car, causing the regulator to fail, or there is something inside the alternator causing it to fail.

I checked the starter and tightened the connections, although they seemed fine.

The engine is stock, stock plugs, stock everything. Harness checks ok, not rubbing through.

Alternator does have the overrun pulley (clutched pulley).

Any ideas?

VET4LES

Sounds like there is something else wrong with the alternator causing the voltage regulator to fail. I would think a good shop should be able to isolate the problem.

KB9GKC

Hello,

A weak battery will put a large load on an alternator. Make sure the battery takes a full charge from a battery charger before you start the car again.

Alternators are not designed to charge a weak battery, they are designed to maintain a healthy battery.

Good Luck,

Douglas in Green Bay

n8dogg

Ended up being the alternator. At high rpm's something internal expands and shorts out the alternator, blowing the voltage regulator.

VET4LES

REDC4CORVETTE

See what fan they installed inside the alt was it plastic like a regular car or the metal one that goes in the corvette alt and cts cady?
Make sure if it is the wrong fan it could be turning the wrong way and overheating the alt.The alt can turn in any direction and charge but the fan inside the alt has to be the right direction.