Interesting problem with my 81 300D: When the temp drops below 50 deg F the drivers side windows (front and back)will not move, but as soon as the temp rises above 50 they work again.

The switch is new

 

What about the passanger side???What happens when you use the individual rear window switch??

 

MC-Professor,

That is a strange problem, but I have an idea, crazy as it may sound, that may fix your problem.

My thought is that the contacts in the window switch group are worn to the point of failure. In extremely cold temperature, the copper contacts inside of the window switch group contract as metal does in extreme cold. This contraction may be enough to cause the the contacts not to touch when you try to operate the windows.

I know this idea may be out there, but it is definitely something to look into. I am not saying that this is the problem, you will need to properly diagnose the power window circuit to know for sure, but the switch group is a good place to start if you think the window motors are not getting power.

If you are interested, we have replacement window switch group available for your car HERE, or by clicking on the photo of the window switch group below. Also, this is a genuine Mercedes-Benz replacement part, so you can be sure that fit and finish will be perfect.



If you have any questions, or there is anything else I can help you with, please feel free to post or send a PM!

 

Plutoe, no the switch on the back door does not work either .

ECSTuning: The switch is new, but I did have to repair it, the top came off, I had to put it all back and super-glue the sides.

Guess I'll have to take the swithch apart again. I thought maybe the mechanism was getting bound, but the switch is the only viable solution. I guess I'll fins out in the fall