Alternator
Drifting
Joined: Apr 2003
Posts: 1,323
Likes: 2
From: Castle Hills Texas
Re: Alternator (Jmccreary)
I believe there were two, depending on your options probably. As I recall one was listed as a 63amp and the other a 70amp. I would over-amp if you are replacing one. It won't hurt anything.
Thread Starter
Advanced
Joined: Jul 2003
Posts: 70
Likes: 0
From: Smithton il
Re: Alternator (Jmccreary)
I just checked and it is stamped 70 amp. I didn't think that they marked them.
Anyway, here is my problem: When the key is turned on and engine is off the battery light comes on bright...which is normal. When I start the car the battery light stays on but is dim. I just had the alternator checked in the car and the result was that everything is normal except the peak amps was low at 39 amps. The tech told me the diode and regulator tested fine. I just read on the internet that a bad diode could cause the amp output to show around 65% of its normal peak rating. So with a 70 amp alternator, 65% of peak would be around 45 amps compared to the 39 peak that it is testing at.
What to you think? Could the diode be bad and the tech's instrument did not properly detect? I called the local Chevrolete dealer and they have a diode for $5. I guess I will get it and put it on.
Anyway, here is my problem: When the key is turned on and engine is off the battery light comes on bright...which is normal. When I start the car the battery light stays on but is dim. I just had the alternator checked in the car and the result was that everything is normal except the peak amps was low at 39 amps. The tech told me the diode and regulator tested fine. I just read on the internet that a bad diode could cause the amp output to show around 65% of its normal peak rating. So with a 70 amp alternator, 65% of peak would be around 45 amps compared to the 39 peak that it is testing at.
What to you think? Could the diode be bad and the tech's instrument did not properly detect? I called the local Chevrolete dealer and they have a diode for $5. I guess I will get it and put it on.
Thread Starter
Advanced
Joined: Jul 2003
Posts: 70
Likes: 0
From: Smithton il
Re: Alternator (Jmccreary)
Went to the dealer last night to get the diode. $4.44, one of the cheaper parts I have purchased. Anyway, I had the counter guy double check to make sure the part was for the 70 amp alternator, just to be sure. He comes back and tells me that they ordered the wrong part and the one they had was for the 63 amp alternator. Incompetence at it's finest or just an honest mistake? Whatever the case I am fortunate that I had them double check. Have to pick up what I hope to be the correct part tonight.
Also, I was driving last night and the alternator light went out. Stayed out until after having dinner at the local resturant, went to start it up and it came on again.
Also, I was driving last night and the alternator light went out. Stayed out until after having dinner at the local resturant, went to start it up and it came on again.
Thread Starter
Advanced
Joined: Jul 2003
Posts: 70
Likes: 0
From: Smithton il
Re: Alternator (Jmccreary)
Update: Stopped by the dealer on the way home from work and they had the correct diode waiting for me. I just put it in and the light is no longer on. I guess that fixed it, all for less than the cost of a value meal at the golden arches.
J
J
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer