Another door died
No passenger front window, no seat controls, door mirror or lock. Failed with the door open, so though the rear window works, it won't raise all the way because it still thinks the door is open. (Still had to dick around with the door card to drop the front window in order to close the damned door!)
On-seat controls seem to work (Pulse, lumbar etc), though the auto seat-forward movement had long failed beforehand - will ask about this later

First place is the usual door wiring in the accordion connector - found a few suspect wires in there including the main live and ground. They are not severed but the brown (N?) and red/blk (L?) sheathing (among some other colours) has opened right up. Hoping to find enough strands have failed to drop the current.
QUESTION 1
I wanted to check before repairing - are any of these wires (inc. SRS) 'resistance-sensitive'? Will adding another 5cm upset any measurements by various modules/CANBUS - or am I reading too much into it?
QUESTION 2
Should I be picking up 12v between the RED/BLK & BROWN heavy-gauge wires on the main 6-pin connector in any key state?
QUESTION 3
Should this not be my issue and I have a Door Control Module problem, where is this located exactly? Remember I am RHD (I don't know if this makes a difference, probably not).
QUESTION 4
Apparently, fuse 13 under the bonnet on the left is for the LEFT DCM. But I don't have a fuse 13. There is nothing in this location - is that normal? I have a 2003/4 car.
Appreciate your help folks!
Last edited by ukcl600; Mar 9, 2021 at 12:24 PM.
Can anybody tell me where the other end of the main door harness goes?
Last edited by ukcl600; Mar 10, 2021 at 01:13 PM.
Just tried a second hand DCM (different part number) - not a sausage.
Cannot make much sense of the WIS diagram other than it continuing to point at F13 in the left fuse box under the hood. I do not have a fuse there.
anybody?
Just tried a second hand DCM (different part number) - not a sausage.
Cannot make much sense of the WIS diagram other than it continuing to point at F13 in the left fuse box under the hood. I do not have a fuse there.
anybody?
unfortunately I don't have any answer to your questions but I suspect a bad connection to the DCM itself. I will be working on that issue through this week (currently working on Stereo upgrade right now)
I will try to check for your questions and will keep you posted with what I find.
As for my car specifically, I got to the bottom of it. Hope this helps someone else.
Turns out I cannot count

The neutral return DOES go back to the fuse box under the rear seat. It terminates on one side of the 25A fusible link.
The live returns to FUSE 13 in the F1 fuse box under the bonnet (Nearside RHD, Driver side LHD). It terminates on one side of a 40A fusible link. (Mine had a 15A in there)
NOTE: The SRS Airbag CAN be disconnected provided the ignition is off. I triggered no codes disconnecting and reconnecting in this way - no need to remove the battery.
This whole thread has been born out of my inability to count the spaces where other fuses would have been on other models. I did not count the first three empty spaces in the long row of fuses in the box (fuse 6/7/8), which is how I 'didn't' get to fuse 13.

Needless to say that the door now works again as it should - with the addition of the keyless go button operating (the harness clip had broken and was disconnected).
As for my car specifically, I got to the bottom of it. Hope this helps someone else.
Turns out I cannot count

The neutral return DOES go back to the fuse box under the rear seat. It terminates on one side of the 25A fusible link.
The live returns to FUSE 13 in the F1 fuse box under the bonnet (Nearside RHD, Driver side LHD). It terminates on one side of a 40A fusible link. (Mine had a 15A in there)
NOTE: The SRS Airbag CAN be disconnected provided the ignition is off. I triggered no codes disconnecting and reconnecting in this way - no need to remove the battery.
This whole thread has been born out of my inability to count the spaces where other fuses would have been on other models. I did not count the first three empty spaces in the long row of fuses in the box (fuse 6/7/8), which is how I 'didn't' get to fuse 13.

Needless to say that the door now works again as it should - with the addition of the keyless go button operating (the harness clip had broken and was disconnected).
Good job on your work, but I would say what happened with you was for a reason (you misread the fuses) so that you would do a post and one day it would help someone else
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My 2003 cl500 is having a similar problem, but it's intermittent; passenger side door clearly has power as all lights are on but upon initial start up and during driving the window won't drop, the heated seat doesn't work and you cannot move the seat or open the door, when trying to drop the window using the driver controls you can hear the actuator activate but the window doesn't drop.
Then, when parked and engine is switched off (but ignition is still on) everything works as it should.
Someone seems to have been in the wiring harness before and it's a mess, but it was working properly when i first bought the car and for 2 weeks. My only thought is that since temperatures have dropped the cold weather has increased the resistance of the wire?
I plugged in a icarsoft diagnostic tool to see if it would give me anything, i've attached a picture of the message.
So, i guess my question is, do i just have a fault wire or door control module?
Cheers.
The Best of Mercedes & AMG



I think at some time I want to take the door panel off, redo all the wires and reconnect them down in the dash. ALL these cars will have issues with the door wires at some point




