W123 drivers window fuse issue!!!!!

[Argospete33]

83 240d that I purchased recently. The previous owner was jumping the drivers window fuse with the wiper fuse. I am trying to fix the problem now as the passenger window works fine as does the rear drivers side. I changed window switch relay behind the instrument cluster as well. When I plug in the switch for the drivers window the fuse pops!!! What should i look for?

[Sugar Bear]

Pull the door card/panel and disconnect the motor at the screw terminals. If the fuse doesn't blow the motor is shorted. There could also be a short in the switch, try swapping in a different one.

Does the fuse blow instantly or does it slowly melt?

[Argospete33]

I plug in the drivers door switch and push it and it pops instantly. So your saying unplug motor and plug in switch and if it pops ?

[ykobayashi]

I am having a flashback of this happening in my 82 240D many many years ago. I’d just bought a new unknown manufacturer switch. MB compatible but not MB

Anyhow when I plugged it in the fuse would pop.

I compared it to my original switch and it had a bus bar across the bottom that would short power to ground. I cut the bar to make the switch look like he original. It was just made out of bronze.

It worked. The fuse stopped popping.

Is your switch new too?

ETA - wait I must be losing my memory. This was on my SD. My 240D had crank windows. So I recall checking the switch out with an ohm meter and I realized the new and old switch were the same except two of the pins were shorted together with this brass bar under the switch. Likely the switch was for the back because it was a single.

[Argospete33]

The switches are both used i assume. Will check again and test it with motor disconnected.

[Argospete33]

The switches are both used i assume. Will check again and test it with motor disconnected.

[psaboic]

Try using a different switch if you can. It sounds like the one switch may be bad.

[Argospete33]

I unplugged the motor as stated above and the fuse still blew again. I reversed the switch and and plugged it in backwards and the rear drivers side worked with child safety plugged in. I pushed on the drivers window and the fuse blew again!!!

[Argospete33]

Could it be the plug side on drivers window plug with the problem? Should I just get a new switch?

[Sugar Bear]

First look inside the short accordion in the door jamb for a wire that has bad insulation/cracked or is pinched. If all looks good there then the next most likely culprit IMO is the switch.

[Argospete33]

I just installed a new drivers window switch and the window went down half way and the fuse popped again!!! !!! I dont know what to do??

[Sugar Bear]

Did you inspect the wires in the accordion boot?

[Argospete33]

I will look at them again..it looks like 2 vacuum lines and the line that feeds power to window motor?

[Sugar Bear]

Yup, Please post a picture of he blown fuse(s).

[Argospete33]

I will take a pic of the blown fuse. It always snaps in half but stays intact. Almost like a cut right in the middle. Before the fuse blew the rear passenger side worked intermittenly and as I was pushing on the switch I can see little spark or light from the rear passenger console switch. When the rear passenger switch on the console does not work you can hear the.motor when pushing down. The switch at rear passenger door itself nothing.
I go ahead and push down on the drivers door window and the fuse pops.