weird charging/alternator problem

[re1vaj]

i have a 94 buick century and having some problems with the alternator or some kinda wiering problem i think. this is gonna be my 3 alternator this month i dont really know if its that alternator again or some kinda wiere loose. some times it starts fine and i can see the voltmeter charging and some time i see it below half and lights go dim i accelerate and gose back up

[ctwright]

Check your battery terminals for good connection and check your grounds.

[richtazz]

Also check youre serpentine belt, tensioner, and other belt driven accessories for any lateral free-play or evidence of bearing failure.