W124 Passenger window switch opens sunroof!

Discussion in 'Electronics' started by scottan, Apr 23, 2015.

  1. scottan

    scottan Active Member

    Messages:
    64
    Joined:
    Apr 30, 2007
    Location:
    London
    Car:
    C240 Sport Tip (gone) C124 E320 coupe
    Must have a short somewhere because the passenger window switch closes the passenger window and opend the sunroof at the same time!!! Not good when its raining!. :eek:
    Where to look...behind the dash?

    Thanks
     
  2. Dec

    Dec Hardcore MB Enthusiast

    Messages:
    4,475
    Joined:
    Jul 28, 2004
    Car:
    C180,A.
    Might be an earth problem somewhere. Taking a look inside the Convenience Control unit, it might yield some clues as to what’s wrong.

    If you open up the unit you will find 8 relays, 4 to raise each window and 4 to lower each window, you could manually close the points on a relay with your finger, depending which relay you operate, the window will either close or open.

    Not sure if this unit has any connection with the sunroof or if there is a relay somewhere else for the sunroof.

    Operating the cabin window switches will click each relay and will identify which relay belongs to which window.



    Dec


    [​IMG]
     
  3. hotrodder

    hotrodder Hardcore MB Enthusiast

    Messages:
    845
    Joined:
    Sep 28, 2008
    Location:
    south east
    Car:
    '93 320te
    There's a relay on the back/underside of the sunroof motor, my random guess would also be to start with the convenience module under the back seat as comfort opening/closing via the key or fob opens/shuts the roof as well as the windows. Off the top of my head that's the only common link between windows and roof?
     
  4. OP
    OP
    scottan

    scottan Active Member

    Messages:
    64
    Joined:
    Apr 30, 2007
    Location:
    London
    Car:
    C240 Sport Tip (gone) C124 E320 coupe
    Thanks guys...already have the seats/carpets out so will take a look tomorrow
     

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