power window failure in '86 300E
 

Yesterday the power windows on my '86 300E went dead. Fuses okay. Relay change did nothing. Where do I look, or what's the sequence of diagnosis?

More info needed...
 

Is it one or more windows? which ones? does it make any noise? any symptoms before this happened?....

try with the doors open and closed??
 

Hi blue,

Try the windows with the doors open and closed. There are 2 switches in the door pillar (A pillar) and one of them is in the elec window circuit. If they work with the doors open, then it could point to a diode in the relay area, at the rear of the fuse box.
I had this problem before, replacing the diode corrected it.

All the best
Gerard

If it is only one window, it may be the switch. I've had this problem twice. Both times I removed the switches (easy job) and sprsyed them with contact cleaner and the problem was solved.
Also, through experience, I have learned that a fuse that looks good may still be the problem. If the metal of the fuse has turned dull through aging it may no longer be making good contact. Sand the ends lightly to return the shine and conductivity. Then reinstall. This has cured several electrical problems for me.

Digging up an old problem here, but looking at a '86 300e to buy and none of the windows work.... Where is this diode that was mentioned and does anyone have a part number for it?

windows don't work
 

With all 4 windows failing to open, I'd suspect an electrical problem too. However, the windows in my '86 300E will fail to open sometimes. I found that, if the windows haven't been opened in awhile, they tend not to work. The problem turned out to be the rubber molding sticking to the glass. I could break the sticking loose if I gently thumped the window around the edges, using my hand, the window would then work. This is most common on the back windows which I seldom open. :D

This may not be your problem but it is a cheap fix. The PO of my car had the rear window switches replaced too often. :eek: