Originally Posted by ah-kay

Fixing window is not as difficult as one may think. You have 4 doors, 2 driver side and 2 passenger side. If you are stuck, look at the other 'working' door. The pain is to remove the panel to look at the good one but MBZ panel is not difficult to remove, a pre-requisite for all MBZ lovers.

Problem with windows:

1) A lot of the time it is the teeth is gone and you are screwed.
2) Or may be motor brushes - possible to replace. I have cut other carbon brushes to size before.
3) gear reduction worn out - screwed.
4) Plastic attachment broke - screwed
5) Frame bent - possible fix
6) May be electric then you are in luck - trace the wires. It is only 2 wires and it change polarity for going up/down. It is NOT connected to chassis.

Look at what is broken and if you think you can fix it then attempt to do it, otherwise get one from a junk yard or buy new.

Good luck.