Buick Skylark 2nd alternator in 3 months

I put an alternator in my Buick Skylark 6 cyl about 3-4 month ago. Two days ago it died again.

Does anyone have any idea why I would go through 2 alternators in 3 months? The car has 96000 miles.

Thanks Joe

Probably a low-quality replacement alternator. There are a lot of them out there..

First one lasted 92k and second lasted 4k

Does price guarantee quality? Or does a lifetime warranty guarantee quality? Some places like Pep Boys sell two qualities. Or new (mostly Bosch) and rebuilt with a lifetime warranty. Unfortunately the labor expended to change the item is much more costly than the part itself in many cases.

Alternators are not usually too bad on labor, but water pumps, etc are. How does one know that he or she is putting in a part that will last as least as long as the OEM?

Phil