Stalls?

[Farrix]

I've got an 02 ranger 3.0v6 edge and its got a couple of gremlins, the main one I can't determine if its electrical/mechanical,

My truck started to stall out at red lights, and whenever the RPM dips below 800, seems like an accessory drive is kicking in causing the tension to go up on belt when the RPM is down *slowing down into corners and crankin hard on the wheel has been a real common stall point*and when the RPM dips the truck just flatlines on me and is a bit more difficult to start then normal afterwards.

I JUST changed my fuel filter on a friends advice shortly after this began and it didnt seem to make a difference, If i maintain over a half tank of gas it doesnt seem to want to stall either

I KNOW for a fact my alternator bearings are going I can hear em screeching from time to time and checked under the hood and followed the sound back to the alternator,

But i'm not certain its my alternator thats causing my truck to just stall out like it is, the battery gauge is reading slightly below normal, havent gotten a multimeter on it yet, will be tommorrow, I'm a little worried it might be my fuel pump or something else, But im NOT getting ANY check engine lights off it (except the one to tell me "Hey... no oil pressure, yer trucks off dummy")

any ideas would be appreciated, a new alternator is 280 and easy enough to get put in but it would be a real burner if i got it changed and it fixed nothing, I just dont know personally how much the alternator could mess with a vehicle this new,