View Single Post
  #1 (permalink)  
Old 10-02-2010, 03:07 PM
Jeep2Xfire's Avatar
Jeep2Xfire
Jeep2Xfire is offline
Forum Regular
Join Date: Nov 2007
Location: Jacksonville, FL
Age: 44
Posts: 743
Likes: 0
Received 0 Likes on 0 Posts
Default F/S Window Motor

Well, my driver side window I thought was totally inoperative. Ends up it will go down and not up. I ripped the door apart to get to the motor and connected my multimeter to the leads and in operating the switch I got 12 Volts on either side. I thought cut and dry, needs a new motor. I ordered one through my parts department who got it from Park Place Benz. Installed the new motor once I got it and the damn thing still doesn't work.

I then looked up the wiring diagram on the window motor. Motors are pretty simple, only two wires since electric motors are reversible. Well, of course Benz had to complicate things.... Seems as though the Body Control Module had a 5V sense circuit that the window switch operates on and then the BCM sends 12V either way along the same two wires to operate the motor. Because I have 12 V on either side of the motor the wiring is good, but the BCM is losing ground (internal to BCM) on the window "up" circuit. I need a BCM not a motor.... Yay for me... <insert sarcasm here>

Below are the pictures of the motor and what not. I am not trying to rip anyone off, I just want what I put into it. Park Place is saying that because it's a special ordered part, it's now mine. That blows...

I will entertain reasonable offers. If you are near the Dallas area I will even deliver or meet you halfway somewhere.

Thanks in advance

Justin