I have 99 s-10 blazer. It has the express power down feature for the drivers side window. My problem started with window not wanting to go up after it went down a couple of times. It then started going up but if you didn't take your finger off the up button as soon as it needs to be the window would travel to far. The window doesn't move in either direction. I have the panel off and the motor exposed. I have ohm ed the contacts on the motor where the plug clips in as it test out fine. The switch has 12 volts to it up and down. The plug has 12 volts as well. The motor does has a little play in it side to side. Loose rivets I guess. I'm wondering before I get into this thing even more If there is anything I can do to know if it is the motor that is bad or something else.

 

If I remember correctly, when I changed my driver window motor, it was fine as well. I didn't test it before I took it off the vehicle, however, once I took it off the vehicle, it seemed to work fine. That said, it was not functioning under the load of the window. I replaced it and all has been well since.

 

Yeah, just from what you describe it sounds like it is more than likely a bad window motor.

 

well I went ahead and changed the motor out. What a pain in the neck that was. My Chilton's said to remove per manufacturers directions. What a joke. It did show a nice picture of a motor and regulator with the rivets that needed to be removed. Besides that I got no help from that manual. The new motor came with directions. Although still a little vague I was able to work through the challenge. After I got the motor bolted up to the regulator, I had to maneuver the piece through a access hole in the door just barely big enough to allow it. Then the fun of getting the plastic bushings in the slots. When I would get one in it was almost impossible to get the other two in without one bushing coming out of the track. Well I hooked up the battery and plug the motor back in to bump the motor helping align the motor and regulator back into position. A full day but now my window works without any problems.