A couple weeks ago my alternator completely died on me. I knew it was on its way out because I could smell the tell-tale burning plastic odor and the red battery indicator light came on. I had a mechanic confirm that the alternator was bad. Not a surprise because this was the original alternator and served me well for 199k miles.

I installed a remanufactured alternator from QualityBuilt (i.e. cheap) and a new serpentine belt. I also replaced the battery because it was over 6 years old and starting to fail. The install took 4+ hours for me to figure out but everything went in fine.

When I started up the car, I could immediately hear a whining noise (see video below) as if there was a bad bearing in my new alternator!? After the car gets up to operating temp, I am once again smelling the same burning plastic odor that (I previously assumed) was coming from the old alternator. I'm 90 percent sure the new alternator is producing this smell because it also gets quite hot even after a short drive. I tried adjusting the belt tension but that didn't change anything. As far as I can tell, the alternator is charging the battery just fine but I'm going to take it to O'Rielly to get it tested and confirm.

What's going on here? Did I get a bad alternator or is there something else going wrong with the charging system? Could there be an issue with the electric load detector (ELD) that is causing the alternator to malfunction? Would that explain the loud noise and smell?

 

If it's not that alternator's pulley bearing it's another bearing. I recommend taking off the belt and spinning the pulleys with your hand until you feel one that feels extra loose or "grindy".