I just became the new owner of a 1991 jeep cherokee friday. I brought it home to give it a look over I cleaned the engine.

 

Sorry on my droid on mistake hit send. Well long story short the drivers side window does not like to roll up I have to flick the switch to get it to move up but it moves down fine. The second issue is I installed a new belt and tightned it so there is little slack but the belt squeeks. the squeek goes away after like a min of driving but come back if I idle for to long. It also doesnt happen if I turn off the ac. I think it might be that I ran the battery low yesterday installing a new stereo and it might be a heavy load but I would like to verify this.

 

Sounds like belt is loose. Serpentine belts get tightened to a tension of 150 to 180 LBS. Go to autoparts store get a gauge for $2. Flex or twist tests don't work like with a V-belt. For the window clean switches and lube mechanism.