I've been having issues with several alternators that was supposed to be correct for my 2000 Vett. On start up it would dip down to 9 volts and you had to rev the motor a couple times to get it to pop up to about 13-14 volts. This happened every time I started it. I believe it had to do with the fact it was not the original Valeo alternator but one that came from the local parts store. Below is some research I thought I would share. Mine works great now!

1997-2000 Alternator replacement:
You need a 97 to 00 Y body 110 amp Valeo French made alternator... no others will work...you cannot use an F body 110 amp, you can’t use any Gm alternator...it is very specific for a C5... your PCM expects to see 110 amps at full duty cycle.. anything more will throw codes...Gm offers a 140 amp Valeo made in Mexico but you need to have it installed at the dealers and they have to reflash your PCM.. it is about a $500. You can have your original rebuilt if you still have it and didn’t use it as a core, or find a used 97 to 00 as long it is an original Valeo made in France with 110 amps. Your car, whether an MN6 or an A4 takes the same alternator regulator. The only part number for your car is 10246634... you cannot cross reference it without taking it to the dealer for a PCM reflash. In 2001 they went to a clutch pulley for A4 cars...no clutch on an MN6.

Here’s the Cross reference numbers for General Motors 10246634
EDR 931425
ELSTOCK 284878
GMC 10246634
LUCAS ELECTRICAL LRA02370
VALEO 2541916
VALEO 439217
VALEO A14VI21
VALEO AR10293A

110 AMP VALEO ALTERNATOR FOR 1997, thru 2002, CHEVROLET CORVETTE 5.7L (A14VI21) – 13721 or 13969
Here’s an alternate fix,

I bought a Autozone Duralast DL2301-16-2 alternator that matches the GM 10246634 for about $180 and replaced the regulator with a Valeo #M530. The regulator cost is about $45. Easy to replace and fixes the issue yourself. Next time, get it rebuilt… and tell the builder about the required regulator.
# M530 - Voltage Regulator / Brush assembly for Valeo 110A Alternators On: 1997-2002 Chevrolet Corvette.

For : Valeo 110A Alternators
Used On: 1997-2002 Chevrolet Corvette 5.7L (350) V8
Replaces: Valeo 593342, 9RC7109, 2541935B, 2546366C, 2546493C, 2542521B, 9RC7109 Unit Nos: GM 10246634, MAGNETON 9-517-186, VALEO A14VI21, VALEONEW 439217, VALEOTECH 2541926

Lester Number : 13721b

Got the regulator from Quick Start Automotive Electric

 

When my alternator went south I took it to an aftermarket re-builder. He new all about what the C5 Corvette needed and put the correct parts in it. Three days later it was running like a champ and no issues in the last 4 years. Still using my original alternator.

 

Damn didn't know this thanks. I hope I remember when my alternator goes out. This should be a Sticky

 

I believe you mean volts