My power window on my 1996 GMC JIMMY wont go up on the driver side. The other 3 work just fine. I'm not real mechanical, but can anyone tell me how to fix it, or what the most likely reason would be for it to just stop working all of a sudden? I can't roll it up,& it could rain!

Power windows are a pain in the ass when they break.

Check the switch. Not broken? Then tear the door apart and see if the gears are caught on something, if that ain't it you will have to replace the motor.

I had to take my car into some rip off place and even though I supplied the new motor, they charged me like $300 to install it. They were real assholes too.

Not familiar with the GMC, but most power window motors only use two wires and the switch reverses the polarity. Take the door panel off, get two jumper wires and a battery. Unplug the connector to the motor, hook up your two jumper leads to the connector going TO the motor and the battery. If the window motor makes a noise but doesn't go up, reverse the leads. If it goes up now the problem is in the switch.