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

blindwolf · #6 08-27-2007, 07:23 PM

I hope this diagram is useful. With this and Brian's wisdom, you should be able to figure it out.

lutzTD · #7 08-27-2007, 08:20 PM

Quote:

Originally Posted by blindwolf

I hope this diagram is useful. With this and Brian's wisdom, you should be able to figure it out.

not sure what the format is on this. it is a .max file?????

lutzTD · #8 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.......

blindwolf · #9 08-27-2007, 10:35 PM

It is a Paperport .max file.

lutzTD · #10 08-27-2007, 11:04 PM

Quote:

Originally Posted by blindwolf

It is a Paperport .max file.

thanx for your effort, but any chance you could make it a jpg, bmp or pdf?

blindwolf · #11 08-28-2007, 07:04 AM

try http:www.nuance.com/paperport/viewers/ for software to read max file

tangofox007 · #12 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.

lutzTD · #13 08-28-2007, 10:33 AM

ok, the front driver window plug has 4 conductors, red, green, blue and black. green and black ohm to the window motor junction on the door

of the four conductor in the plug, blue is the front, red is the back, and green and black are on the two sides.

if i jumper red to either side and and blue to the opposite, my dash lights come on

if I jumper red to green and black to chassis ground the window will move

if I jumper red to black and green to chassis ground it moves in the opposite direction

I think I can safely say the motor, wire harness and connector are ok.

so my question is why isnt the switch getting ground in the up position?

The above posted diagram is too small to read and the viewer will not zoom, does anyone else have a diagram of this switch?

Thanx

tangofox007 · #14 08-28-2007, 12:17 PM

From looking at the wiring diagram, I don't see how the problem can be anything but the switch, based on the information provided. "Up" and "down" both use the same basic ground.

Here is the set-up for the front part of the driver's window switch:

Terminal 3 (red): 12 volts for window operation
Terminal 1 (green) power or ground to motor
Terminal 2 (black) power or ground to motor
Terminal 4 (brown) ground for front window
Terminal 5 (brown) ground for rear window safety switch
Terminal 6 (blue) power for switch illumination

With the switch in the neutral, both the green and black wire supply power to the motor simultaneously. The switch breaks the connection to one or the other (depending on window direction) and connects that wire to ground through terminal 4.

lutzTD · #15 08-28-2007, 12:31 PM

Quote:

Originally Posted by tangofox007

From looking at the wiring diagram, I don't see how the problem can be anything but the switch, based on the information provided. "Up" and "down" both use the same basic ground.

Here is the set-up for the front part of the driver's window switch:

Terminal 3 (red): 12 volts for window operation
Terminal 1 (green) power or ground to motor
Terminal 2 (black) power or ground to motor
Terminal 4 (brown) ground for front window
Terminal 5 (brown) ground for rear window safety switch
Terminal 6 (blue) power for switch illumination

With the switch in the neutral, both the green and black wire supply power to the motor simultaneously. The switch breaks the connection to one or the other (depending on window direction) and connects that wire to ground through terminal 4.

I dont have a brown wire, am I missing a brown wire or is it coming from the back half of the switch. the thing is, the new and old switch had the exact same issue. that is why I find it more difficult to believe it is the switch

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