driver window goes down but not back up - PeachParts Mercedes-Benz Forum

lutzTD · #1 08-27-2007, 05:54 PM

i have a driver window that goes down but not up. if I switch the wires on the door it will go up. i have a brand new switch and I have ohmed the wires to ground they are not shorted. can someone post the window wire diagram for an 84 300D? I cant figure this out and it is aggrevating that i have to drive my "good" car because of a window on my beater

Brian Carlton · #2 08-27-2007, 06:04 PM

I once had similar issues with a window switch on the SD. Would blow the fuse instantly when the switch was depressed. I finally determined that the switch was defective.........several contacts were common with each other and should not have been. Switch to the "good" switch from the driver's side and it was OK.

Try the window with a known good switch and see what you get. Your motor and wiring appear to be good.

lutzTD · #3 08-27-2007, 06:10 PM

so heres the weird thing, the new driver switch runs the passenger window down but not up. the passenger switch wont run the driver window at all.

I am hesitant to blame the switch since it looks brand new, if I had a diagram I could cross the terminals to duplicate the switch function and eliminate it from the trouble shoot exercise

Brian Carlton · #4 08-27-2007, 06:23 PM

Quote:

Originally Posted by lutzTD

so heres the weird thing, the new driver switch runs the passenger window down but not up. the passenger switch wont run the driver window at all.

I am hesitant to blame the switch since it looks brand new, if I had a diagram I could cross the terminals to duplicate the switch function and eliminate it from the trouble shoot exercise

I only have the diagrams for the W126. However, look at the wires that head into the switch. You'll probably find one red........one brown..........and two of an alternate color. The red is the 12V supply power and the brown is ground. Check for this with the keyswitch on.

The two remaining wires go to the motor. Put 12V on one and ground on the other. Then reverse them to drive the window the opposite way. If the window goes up and down when you do this procedure, the problem is the switch.

lutzTD · #5 08-27-2007, 06:55 PM

Quote:

Originally Posted by Brian Carlton

I only have the diagrams for the W126. However, look at the wires that head into the switch. You'll probably find one red........one brown..........and two of an alternate color. The red is the 12V supply power and the brown is ground. Check for this with the keyswitch on.

The two remaining wires go to the motor. Put 12V on one and ground on the other. Then reverse them to drive the window the opposite way. If the window goes up and down when you do this procedure, the problem is the switch.

thats what i was looking for, thanx

lutzTD · #6 08-27-2007, 08:41 PM

Quote:

Originally Posted by Brian Carlton

The two remaining wires go to the motor. Put 12V on one and ground on the other. Then reverse them to drive the window the opposite way. If the window goes up and down when you do this procedure, the problem is the switch.

i was skeptical this sounded too easy, all it does is light up the dash lights.......

tangofox007 · #7 08-28-2007, 08:58 AM

Quote:

Originally Posted by lutzTD

i was skeptical this sounded too easy, all it does is light up the dash lights.......

Try 12 volts to the black wire and ground the green wire on the switch receptacle. Those shoud be the only two wires that actually connect to the motor.