94 Dodge spirit

[SINCITY192]

My sister keeps having this problem where her new belt breaks in about a week or two, she has 2.5 l engine TBI i believe, I have change her belt 2 times since i came down here and she has had it change at least 2 other times in a shop.
I read somewhere that it has to be a pulley but its the belt that runs from the alternator to the crankshaft pulley, she says her alternator is new??? any ideas?

 

[XJLI]

damn, i remember my 2.2 sundance being a bitch with the tensioner when i changed the belt.. i think i replaced a pulley and bracket thing with a junkyard piece when i did it, but it was like 7 years ago i cant remember.

 

[Dundy]

Bad or misaligned pulley.

 

[SINCITY192]

this is my sisters car so its take me awhile sometimes to get to get to the car. But she came over and with her belt ripped to shredds same belt, it runs from the crank pulley, then routed around the water pump pully (smoove pulley no grooves) and then onto the alternator
Now when I line the alternator up with a straight edge and tight the pivot bolt the alternator automaticly slides towards the left (standing in front of the car)
Now I put the new belt tried to jam a long screw driver to stop it from sliding but it still sure enoughs slides about a half a inch to the left and rest there.
I put the belt on any way and it all looks straight but when i start it and watch the belt in question, I can actually see the belt is sliding towards the left to the tip of that pulley which would make since why its ripping up like that! But which pulley is bad the water pump pulley or the alternator?