today the windows on my 1988 560 sl would not operate. checked and replaced the fuses but no help. took out the multi-meter and found no voltage at the fuse box for the window fuses, but voltage to everything else. the car has not been driven much lately. i think there is a relay for the windows but am not sure if this possibly could be considered part of the problem. it would seem to me that the relay would have to be after the switches, so the voltage would come from the fuse box to the switch and then to the relays when the switch was activated. i would guess that the ignition switch would supply voltage to the fuse box to operate the windows, and we have had a "condition" which i have heard is common with some cars that the key has to be jiggled when "on" to start the A/C compressor, which is the case with this car. could it be time for a new ignition switch, which i can surmise would be a major pain?? both windows have no juice and i would appreciate any leads that i could pursue with this problem. thanks. steve

Have the identical power window problem... fuses and switches are new and fuse contacts in the fuse box are clean. Is there a relay in the power window circuitry of the '86 560SL? Is so, where?

I had the same problem in my 450sl. There is a group of relays above the fuse box. The panel around the fuse box has to be taken off to get to the relays.

Dropped the right lower dash access panel and renewed the power window relay. Problem solved. Thanks.

Thanks for the tips. Passenger window stopped with the window rolled up, fortunately.
I checked the fuses on that sidewall. The fuse was good but had popped out; I remembered I had tried to roll both windows up at the same time ( I won't do that again.). I replace the fuse even though it was still good; window fixed.