I have a 90 300d 2.5 turbo. The driver's power window works fine. All the others don't. The three remaining windows make a click in the relay under the rear seat when you push the button in the console or on the door. The front passenger window also seems like it is getting power to the motor because I hear a sound in the door. The safety switch seems fine. I tried changing switches with some other used ones and no change. I have almost 12 volts (11 volts with ignition on) at the rear window switch in console. I took apart the big relay under the back seat and opened it up. It looks fine. As my next step, Should I take apart the door and try the motors with 12 volts? Or just open up the rubber that covers the wires going to the doors and look for broken wires?
Which wire should I check for voltage on coming out of the convenience relay under the rear seat?
On a positive note, I fixed the power seat switch today. It wasn't sliding back, but after a bit of work it is now working. I also recently fixed the oil leak at the tensioner bolt, replaced the vacuum pump with the updated version, and replaced the tensioner pulley. The brakes are working better after cleaning up the sliders and replacing the boots. Now I am just waiting on the right tool to take the exhaust off up by the turbo to bring it in to weld a new flex pipe in.