Electric Window problems

[scotty474]

Hi I'm new to this site and new to the world of Merc's. Have a 1988 300TE Estate (Auto). Beautiful car to drive with just under 200K should last a while yet. However the left/hand front and right/hand rear electric windows have now packed up. The drivers window and left hand rear are ok. My knowledge of electrics is pretty awful but have managed to carry out the following.
Swapped switches around - no luck
Removed relay - no windows at all.
Tried another relay - no luck
Fuses have been swapped - no luck
Have power at all switches.
Haynes manual differs in opinion as to which fuse covers which window so I am somewhat sceptical about the wiring diagram.
Has anyone ever come across this before? Am I being really stupid?
Is there anything else I can try?

 

[anyweb]

i believe it's a common failure on those models, if you can remove the door card on one of the failing windows and use an extra battery, you should be able to raise/lower the windows, does that work ? if so you may have a problem with broken wires in the corners of the door (where the wires enter the door)

cheers
anyweb