Why will my driver side window not go down?

I have a 2002 GMC Sierra SLE 1500, with half back seat. My driver side window will not go down. Before it stopped going down this window would go up and down really slow. However, now that it has stopped going up or down, it is stuck in the up position. When I push the button I can hear the motor going and I can hear some grinding or rubbing. When I do push the button downwards, the window will drop a centimeter or two and than I push the button in the up direction and the window will go up just as far as it went down. I do not believe it is the motor because I can hear it running. What else could it be? I have no doubt the motor might be going out as well but as of right now it is still running, the window is just not being lowered all the way.

Comments on "Why will my driver side window not go down?"
More: All places on a honda dirt bike were model number is located? Hi, I have a 2008 colt cz30 and the radio doesn't have an aux in or usb. Is it possible to change the radio for another one. Thanks.? 2001 durango well not stay idliing as i try too start it. problem SOLVER.? What's the cause of my toyota shift lock i pressed shift lock button it shift but when i shift it to park it is stuck again!? Any idea about Transportation Management Systems?