I have a 1990 190E. The Left Rear window was inop. I installed a new window regulator (it went in pretty easily) and it unfortunately didn't work. I tested and trouble shooted by referencing the CD-ROM, and I don't think it's a bad switch or wiring; I swapped out the switches and also applied power directly -- the motor seems to be getting power correctly. But it doesn't move the window up or down. For now I've left the new one in there. Any suggestions?

Thanks for your help.

Dave

Did you try to move the window up and down without the window regulator? It may be the track that is bent, not allowing the window to go up. Also, did you apply power directly to the new motor ? the old one? in the car?

1) Put a VOM meter or test light at junction block inside door panel where motor wires connect. That will tell you if you have juice to the motor) If you do: switches and wiring can be assumed to be OK.
2)Assuming you used the old motor, remove regulator (to eliminate track as problem) and apply 12v. directly to motor. If the motor doesn't spin, the motor is most likely at fault. Remove motor from assembly (be careful with worm gear)and wiggle armature out. There is a bushing at opposite end from gears with typically two oil access/drain plastic caps. Get some lube down in the bushing, line up the shaft of the armature with the bushing (a movable target) and reassemble(twist and wiggle with the gear, again)
3)Check plastic gear in gear box from motor to make sure it is not chewed up.

I repaired two regulators with frozen!! motors (beach cars) rather quickly with zero parts expense by lubing the bushing. I don't know what you are supposed to use for lubricant (I used sewing machine oil), but since the motor sits vertically, with bushing end down, I wasn't too worried. As always the Secretary will deny all knowledge of your mission. ;)

Many thanks for the help! Will try these over the weekend. The window slides up and down easily when not attached to the regulator. The wires on both sides of the switch are delivering power correctly. I think the situation is that I had the bad luck to get a replacement regulator with a bad motor.

Thanks again for the great advice.