Need help with Power Window diagnosis
 

I have an '84 300D... I've been searching through posts for help, but my eyes are tired, as is my body (I've done body work, engine tune-up, and WVO conversion on this thing for the past few weeks) and I'm hoping there is someone out there that can pinpoint my problem. My driver's side window will not go down. Here's the history:

- Driver's side switch failed... I cleaned it and it still didn't function. Bought aftermarket, installed while taking a break in my WVO conversion, and the left front and left rear windows worked fine.

- Monkeyed around under steering wheel and in console behind climate control to wire for switch and new gas gauge for WVO. Soon after, the front window would not go down. THought I might has dislodged fuse, but right rear window has no issue.

I'm thinking that I may have loosened wire below dash OR that when I tied into fuse box (one is tied into the screw hole on the copper plate between fuse a and b... the fuses for the pwr windows), I might have done something I shouldn't. Electrical stuff is not my forte...

I don't think that it is a problem with the mechanisms... there was not a single hint of strain in the window motor prior to it's recent malfunction.

Thanks in advance for any guidance!

If the RR window works properly and the LF window does not, the chances are strong that there is power to the switches and the problem lies between the switch and the window.

You can confirm this by pulling out the new switch and unplugging it. With the key on, check for 12V at one of the pins. If you have 12V at one of the pins, then the problem must be either the switch, the motor, or the wiring between the two.

Many of these window issues are intermittent due to contacts that are not clean.

They can drive you crazy. Ask me how I know. :(