Charging System

I have a 2001 Pontiac Grand Am SE 2.4L, 4 cylinder car. Had a bad alternator. Replaced alternator and battery. It all worked fine for about 2 days. Then more issues.

It runs fine for about 5-10 minutes. Battery voltage with alternator charging at 14.5 - 14.6 volts. Then the voltage drops to 12.5 and continues to drop. I have checked all the ground points that i could find on the car, no loose terminal connections to the battery, fusible link is intact. battery checks out good. Fuses are good.

Does anyone know what could possibly be causing my alternator to go from working perfectly to not working at all in 5-10 minutes. Im clearly missing something here. Any help to point me in the right direction would be greatly appreciated.

Bad regulator? Have the alternator checked out... on the car.

You won't be the first person to get a bad alternator out of the box.....

I agree. I had 3 in a row, at which point I went to a different supplier. And the 3 bad ones were not aftermarket if you read between the lines.