Repeated alternator failure
Thread Starter
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Repeated alternator failure
I had a new stereo installed in my '79 a couple of weeks ago. Immediately after it was installed, my alternator failed. Coincidence, right? Replaced it with a rebuilt unit from NAPA. 200 miles later, it failed again. I rebuilt the first one myself, and reinstalled it. Failed within 100 miles. I'm beginning to think its not coincidence. I have gone through the installation and everything looks OK. What would cause an alternator to fail?
Thread Starter
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Yeah, I realize the replacement alternator parts we are getting these days are crap, but before I install a fourth alternator, I want to make sure there is nothing wrong that will take out another one. Anyone know of anything that will do that?
Thread Starter
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Head unit, two amps, sub. Total draw is 20-30 amps. Alternator is 63 amps. As far as I know, an undersized alternator will result in a discharged battery or dim headlights. I don't see any reason why that would result in multiple failed alternators.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
A 63 amp alternator is designed for use with a car using 30 amps or so on a consistent basis. Start loading it at 50 amps on a consistent basis, and see how long it lasts. I think you need to upgrade the alternator to an 80-100 amp unit (plus upgrade positive and ground wiring which will carry that additional load).
