I am at wits end and hope someone on this forum can steer me in the right direction:

I have a 2003 Corvette Coupe. Automatic. All stock. One owner. 120,000 miles on it. Meticulously maintained (mostly by the local Chevy dealer)

A month ago I suddenly had an issue where when I am driving the car it was fine until I would pull up to a stop light or stop sign. Then I could watch the battery gauge start to drop 14V...13V...12V...11V....etc. as I would sit there with the engine running and my foot on the brake.

When the light changed, I could pull away and everything would seem to work fine. Battery gauge goes back to normal.

The dealer said it was the Alternator. I found that hard to believe, the original had made it to 102,000 miles and was replaced less than 3 years ago.

They installed a new alternator, then I picked it up, drove it back to my office and parked it for a week. Went back out...battery is completely dead.

Took it back to the dealer, they said there was a 0.8 Amp draw in the system somewhere. They did some diagnostics and decided it was the Alternator they put in. Replaced it again.

Then they called and said the new Alternator was not "charging the system". Gave me some excuse about how there seems to be two types or "styles" of Alternator for this car.

They ordered another alternator. Installed it. Same problem.

Now they think the car could have a wiring harness issue or ECM issue.
They want another 4-5 hours of diagnostic time to figure out what is going on.

Any thoughts on what the heck is going on with my car ?

 

1st thing, they sound like idiots, changing parts without knowing the real problem.

Need to do some testing and see what is actually causing the draw.

http://forums.corvetteforum.com/1567522286-post590.html

Trace it down by pulling fuses and / or relays while monitoring current.

 

Got another call from them today. They claim the draw is gone. But the Alternator is not charging the system. They claim now that it is a short in the wiring between the alternator and the ECM. They claim to be tracking it down...

 

Is it or was it setting any codes? A short of the alternator would cause some SMOKE for sure, an OPEN seems more likely (but what do I know with only 2 degrees in Electrical Engineering). Did they use a Valeo (sp??) alternator like the original? Bet by the time they're done the diagnostics will cost more than the alternator and I bet an alternator at the dealer is a STAGGERING price. Lets see if they can get to $2K on this repair.

 

I paid them about $585 for the first alternator they put in.

Yesterday I told them we are starting at ground zero. I owe them nothing and we are starting the clock again. They agreed. (It helps that I am friends with the owner)

 

I can tell you this much: We just bought a 2013 Grand Sport convertible to replace this one in March of this year. It will be serviced by Les Stanford Chevrolet in Dearborn Michigan (one of the top 5 Corvette dealers in the country).

 

We'll if this dealer is in the top 5 and they're having issues with an alternator, that's not saying much for Chevy dealership service these days.

 

I have had wierd electrical problems and error messages with batteries and charging systems that check out good. Most of the time the problems disappear when I have replaced the battery for other reasons. Put in a known good battery first before spending a lot of time and $.

 

Thanks for logging in, checking the thread, and taking the time to respond!