Power Window Wiring Help - PeachParts Mercedes-Benz Forum

running-snail · #1 03-13-2007, 09:42 PM

It was a warm day in Michigan today. Went shopping, while on the way to the store we put some of the windows down. Passenger front and rear would go down but not up - unless you opened the door!

I've searched and searched. I'm convinced this is a wire short in the pillar - black tubing issue. I've seen several comments like: replace wire; put in new wire, etc.

That's great, but exactly where do you splice the wire? Where does the wire go once in the pillar - to the floor? What has to be removed to splice in a new piece of wire? What size wire was used? Solder & shrink?

Sorry to be so inquisitive - I'm far from comfortable working with electrical issues.

Thanks.

tangofox007 · #2 03-13-2007, 09:59 PM

Quote:

Originally Posted by running-snail

Passenger front and rear would go down but not up - unless you opened the door!

Which door?

running-snail · #3 03-13-2007, 10:10 PM

Thanks for the reply - your post is one that I saw in my search!

Both the passenger front and the passenger rear did the same thing: went down but not up (unless the door was opened).

Bio300TDTdriver · #4 03-13-2007, 10:19 PM

I'm not sure about the w123, but on the w124 the insulation on the wires was too thin. It would break where the wires go through the rubber piece that protected the wires in between the door and the pillar. I pulled mine out and soldered the wires together and either wrapped them in electrical tape or painted on some liquid electrical tape. It's been several months and so far they have held up. Mine were broken on the rear door on the passenger side.

This explains it better than I can. http://**************.com/node/54

Chris

tangofox007 · #5 03-13-2007, 10:31 PM

Most probably you have a broken wire. They tend to break due to the flex which occurs when the door is opened/closed.

The rear window is a little easier to deal with because the offending wire is probably between the console switch and the rear door switch. If you remove both the console and door switch, you can do a continuity check of each (corresponding color) wire at the switch plugs. The '82 wiring diagram shows that a blue/white wire provides "up" power to the RH rear window. When you find the wire without continuity, you can cut it at the doorpost and route a new wire to the door switch connector.

The front door has only two wires going to the motor, as there is no door switch. So you will need to remove the door panel.

In both cases, you want to replace the segment of wire that is subject to flex when the door opens/closes.

toomany MBZ · #6 03-14-2007, 12:33 AM

I have had similar problems, I think it's a dirty, or failing switch. Sometimes it works, sometimes it doesn't. Mine is working today. Could be a wire problem, yet on the 123's I can't determine where the broken wire would be. Much slack, and give. Could be pinched somewhere. I've had panels off, open and close door, no obvious point of break. Good luck.

running-snail · #7 03-14-2007, 08:37 PM

So I can get at the rear door wires by pulling the door post (b-pillar) cover for one side and removing the door panel to get at the other side???

tangofox007 · #8 03-14-2007, 08:43 PM

Quote:

Originally Posted by running-snail

So I can get at the rear door wires by pulling the door post (b-pillar) cover for one side and removing the door panel to get at the other side???

There should be no need to remove the rear door panel. Just pull the door switch out, along with the connector (plug.)

running-snail · #9 03-14-2007, 09:03 PM

I'm feeling really stupid:

I understand the 'pull the switch' rather than remove the door panel.

How do I get at the other end of the wire - in the door pillar?

tangofox007 · #10 03-14-2007, 11:30 PM

Quote:

Originally Posted by running-snail

How do I get at the other end of the wire - in the door pillar?

At the console switch. Check continuity between the console switch and the rear door switch. (If a wire is only "somewhat" broken, you could get continuity even though the wire won't carry enough current to operate the window motor.) Once you have identified the offending wire, you can cut out the section from under the pillar trim to the rear door switch and splice in a new wire. (The wires under the pillar trim should be bundled in a sheath.)

Phil · #11 03-15-2007, 10:00 AM

Quote:

Originally Posted by Bio300TDTdriver

I'm not sure about the w123, but on the w124 the insulation on the wires was too thin. It would break where the wires go through the rubber piece that protected the wires in between the door and the pillar. I pulled mine out and soldered the wires together and either wrapped them in electrical tape or painted on some liquid electrical tape. It's been several months and so far they have held up. Mine were broken on the rear door on the passenger side.

This explains it better than I can. http://**************.com/node/54

Chris

Thats the first time I have seen that link. I'm glad to see pictures of this as I have been tryed to explain this condition many times in the past.
Thanks for posting that link
Most problems that I have had with windows. seats and drivers door locks have been due to this condition