1981 300TD. The left rear window usually goes down 90% of the time (with either switch) and up 40% of the time. Tonight, it wasn't coming up, so it was off the the search function and braingear. I took the door apart, disconnected the window from the regulator, pushed it up and removed the regulator so I could play with it. I can hear it engage to go down when I push the switch, but not to go up. I tried the switch from the right side and got the same result. As a last resort, I ran wire straight from the battery to the leads between the switch and the regulator. Voila, smooth quiet running both up and down.

So, I think the problem is in the wiring, especially since it has the same behavior with both switches. Any ideas on how to trace this or where to start? What's the best wiring diagram source?

Mike

PS, I LOVE working on this car. The leads are actually NUMBERED!