Alternator Issues, Bearings? Options

[Britain Smith]

I replaced my alternator a couple of weeks ago because the bearing went out and it was make an horrible grinding sound. I used a Bosch unit from HPH and everything went fine. Yesterday, I was driving around town and when I came to my desitination I heard a very similar grinding sound coming from the front of the engine. About 15mins later I started the car back up, the sound was still there but not as loud and now the red alternator light was on. Then, after work I was driving the car home and the sound was not that obvious but the light was going on and off and a bit dim at times. When I got home, I opened the engine lid and could hear the alternator spinning as it sounded like it was dragging or something. When I turn the car off you can hear it grinding a bit after all the other noises stop.

Has anyone had any issues with the bearings going bad in freshly rebuilt Bosch alternators? Any other ideas? The belt is tight and everything else looks good. I really don't want to have to go through replacing the alternator again...it looks like I will be though. What is the best way to test the alternator both inside and outside the car?

-Britain