Correct Alternator for '99
Thread Starter
Burning Brakes
Joined: Mar 2011
Posts: 1,048
Likes: 5
From: Metairie LA
Correct Alternator for '99
Here's the deal-found a new alternator for sale here at a good price that I was considering buying for a "spare". P/N is 10246634, which is listed for '03 only. Using the VIN, the P/N called for is 10316182. Dealer says this is a 110 amp unit, and parts application appears to be '97-03. I have searched threads here and some have said you MUST use the 6634 as it is 110 amps. If you use the 6182 you must reflash the PCM because this unit is 140 amps. NOW I'm confused-wisdom here says one thing and dealer says another (nothing new). Any help???
Cruising
Joined: Jan 2000
Posts: 12
Likes: 0
From: Decatur GA
I have been led to believe that the '99 vette was built with both 110 and 140 amp units. I'm not sure if it was by build date or some other factor.
I have a '99 and replaced my alternator with a 110 amp unit. I immediately got a "Charging System Fault" on the DIC, even though the voltage looked OK. Found out that I originally had a 140 amp unit, and had to go back to the 140 amp to prevent the fault message. I was told by my tuner that the PCM is programmed differently depending on the alternator used, which was the reason for the fault message.
I have a '99 and replaced my alternator with a 110 amp unit. I immediately got a "Charging System Fault" on the DIC, even though the voltage looked OK. Found out that I originally had a 140 amp unit, and had to go back to the 140 amp to prevent the fault message. I was told by my tuner that the PCM is programmed differently depending on the alternator used, which was the reason for the fault message.
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
From what I can determine in the listing below, the 182 and the 634 are both rated at 110 amps, and either one would be correct for your '99.
http://parts.nalleygmc.com/showAssem...rimLevel=15135
http://parts.nalleygmc.com/showAssem...rimLevel=15135
Thread Starter
Burning Brakes
Joined: Mar 2011
Posts: 1,048
Likes: 5
From: Metairie LA
That's the way I read it, but the dealer, when using a VIN based parts search, comes up only with 6182. When I asked about 6634 they told me it wasn't for my car? So that was my question-already looked at the Nalley site-that's my primary source at home.
Tech Contributor
Joined: May 2008
Posts: 3,100
Likes: 17
From: Somers, CT and Clermont, FL
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16
FWIW, post #4 in the thread link below claims that the 634 is correct for years 1997-2000.
http://forums.corvetteforum.com/c5-p...0246634-a.html
You could always send a PM to Evil Twin for verification. He is a retired GM engineer, and was part of the C5 design team.
http://forums.corvetteforum.com/c5-p...0246634-a.html
You could always send a PM to Evil Twin for verification. He is a retired GM engineer, and was part of the C5 design team.
Last edited by Quicksilver Vert 01; Dec 29, 2012 at 07:43 PM. Reason: Added info.
