I have a 1999 Blazer 4X4 LT 4-DR. My driver's side window starts to go down when I press DOWN, but 3-4 inches later it stops, but the motor is still running. It sounds like the gear is not attached at that point, or it is not meshing properly. You can feel the bouncing from the motor, but the window will not go down further. When I press the UP button, the window goes up, but when it is up, the motor is still running. Again you can feel the bouncing from the motor, and it sounds like the teeth are stripping or slipping. Where are the limit switches? Does the motor know where it is at? Is the regulator faulty? Any suggestions to check? Help please.

 

That's a problem with the regulator, you'll need to remove the trim panel and see what's going on.

http://shop.advanceautoparts.com/web...022_1708989487____

 

I already have the panel removed. A visual inspection shows nothing out of the ordinary. Do you think the gearbox is defective in the motor? Where are the limit switches?

 

There is a "clutch" of sorts built into the motor and it may have "issues". It is part of the motor assembly and not serviceable other than replacing the motor. There are no limit switches; when the glass reaches full up or full down position, it binds up. Disengage the motor from the regulator and make sure the regulator slides the glass freely in the tracks. If it does, you'll need a motor.

 

I had the same problem, I had to replace the motor

 

I am having the same problem with my 2000 LT 4x4 4.3 for some years now. I have already purchase the "New" motor not "Rebuilt" for around 30 bucks and change. I just haven't taken the job on yet. I hate peeling back that black paper on the side of the door, you can almost never get it back right. Plus this motor has an added surprise, its spring loaded. So one must be careful in removing it or you can get hurt.

 

Thanks everybody for responding...upon further inspection I was able to get the window down and up by helping it out until a section of teeth on the drive gear passed...this happened on every rotation of the motor...so I just purchased the motor...just got it in UPS, and will replace it tomorrow...it's raining...I will let everyone know.

 

OK, finally I could get to my window motor. Why does the reulator need to be taken out and if you need to drill a hole to lock the gear and the regulator together with a bolt and nut, how do you move the gear to get it out of the way of removing the old rivets?

 

You have to get the window into the appropriate position before locking it into place.

 

OK, I finally had the chance to replace it...what a pain in the behind. It shouldn't have been a pain, but I followed some bad steps just because the very first item was never stated. The window MUST be at least half-way down, otherwise, you will not remove the regulator. Now the regulator MUST be removed so you can fasten the body in a vice to move the regulator sprocket out of the way of the old rivets. Caution MUST be taken, because as soon as the motor gets removed the counter-balance spring will want to release the regulator mount quickly, and anything in the way could get deeply injured if not cut-off. What I did was to drill a hole in both the sprocket and the mount plate, cut 1/4-20 threads with a tap, and screwed a 1/4-20 bolt through both parts so nothing releases. I made a tool out of a 1/2" pipe and (2) 1/4-20 bolts. The bolts are going through the middle of the pipe perpendicular to it, one at one end and the other at a distance equal to (2) of the regulator mount plate rivet holes...the idea is to place nuts on the bolts on the tool, put the bolts through the mount plate rivet holes, and then another set of nuts on the tool bolts. The mount plate is sandwiched between the nuts on te tool bolts, and what you have is a leverage bar to move the mount plate. Remove the motor. Holding onto the leverage bar, remove the bolt from the tapped hole, and rotate the plate to clear the motor rivets. Remove the old rivets, and replace with the special tee nuts that came with the new motor. Align the assemblies back together and screw the bolt back into the tapped hole. Now, bolt the new motor onto the mount plate and tighten. I used blue Loctite on all replacable bolts. Your regulator is ready to be reinstalled. Do not forget to remove the locking bolt from the tapped hole once everything is in place. A little tip: before removing the motor after mounting the special tool, note the mechanics of the spring and be aware of the unwinding rotational direction. I did not know what force the spring was going exert, so my tool might have been a little overkill, but I had no problems exerting opposite force to move the assembly out of the old rivets' way with my fingers nowhere near danger. It is not a lot of force, but be ready for it. To give a visual representation of the tool I made, it looks like a long "F".