Need 300D Electrical help ASAP

Mom is due to make the 200 mile trip back home tomorrow in her 1984 300D and the left rear window is stuck in the down position. So far I've swapped switches from passenger side to driver's side - NG. Fuse is good, have 12V to the switch. While I'm well versed in electronics, I've found MB does things much differently from USA (pneumatic door locks for example), and without a wiring diagram I'm finding myself lost.

Does anyone have any knowledge of '80s MB wiring or know where I can go online to find out? I really need a wiring diagram for the windows.

I'm guessing that the motor is probably bad, but I'm sure it is a very expensive part. I don't want to replace it unless I'm certain it is the cause of this. TIA

Roy

sometimes these older motors can get water in the screw mechanism that raises the window up and down and this washes the grease out , then the switch is held for too long in the up or down position which causes this mechanism to get stuck.
to un stick, take the motor case off of the motor leaving the armature hanging then physicly turn the armature to unstick to the mechanism screw the armature out to grease the acme drive screw careful putting the case on, you must get the brushes right.