w124 windows only open when one of the doors is open on coupe/convertible

Discussion in 'Interior' started by dinoy, Oct 1, 2011.

  1. dinoy

    dinoy MB Enthusiast

    Messages:
    1,999
    Joined:
    Feb 15, 2010
    Location:
    london
    Car:
    mercedes of course
    anybody can advise if there is a relay that control the openning and closing of the windows. presently a fault developed whereby windows will only open if a door is open.

    i am hoping somebody can shed some light if there is a relay that control this and where it would be located.

    alternatively a fix reset if there is such a thing
     
  2. Pontoneer

    Pontoneer Hardcore MB Enthusiast

    Messages:
    13,415
    Joined:
    Aug 19, 2002
    Location:
    Ayrshire
    Car:
    '99 S320 W140 ; '93 300SL-24 R129
    There is a relay which enables the window function either with ignition on or doors open . It may be the comfort relay , but I am not certain . You could determine by unplugging each relay in turn until the windows no longer work even with the doors open . Once you find that relay , open it up and look for dry solder joints inside - other relays suffer from this problem so it is worth a look . Otherwise see if you can obtain a used relay from a breaker , or if you know another Merc owner see if you can substitute the same relay from their car to see if it solves the problem , new relays will be fairly costly from the dealer .

    Members on here who break Mercs ( Ian Walker or Retrodave ) might be able to help with a used relay .
     
  3. jaymanek

    jaymanek Authorised Forum Sponsor Authorised Forum Sponsor

    Messages:
    16,412
    Joined:
    Nov 29, 2002
    Location:
    Nuneaton Warwickshire
    Car:
    Lots of Mercedes!
    Im guessing the wiring has worn through at the hinge...
     
  4. jonnyboy

    jonnyboy MB Enthusiast

    Messages:
    2,562
    Joined:
    Nov 27, 2005
    Location:
    Camberley, Surrey
    Car:
    1991 sl300-24 project,s124 280,w115 no interior, w108 project no engine
    Cant remember if a 124 is the same but on a 126 i had the same problem. In the fusebox near the relays is a small diode unit approp 15mm x 15mm x 10mm IIRC, with two pins. I replaced that and all was good
     
  5. Pontoneer

    Pontoneer Hardcore MB Enthusiast

    Messages:
    13,415
    Joined:
    Aug 19, 2002
    Location:
    Ayrshire
    Car:
    '99 S320 W140 ; '93 300SL-24 R129
    If just one window had failed I would agree , but all four stopping at the same time won't be wiring .

    I'm not sure either if 124's have the fusible link like the 126's ( IIRC the device is a thermo-resetting fuse , as also found in 123's ) .

    I will check when I pick my new 124 up in a week or two .
     
  6. trapperjohn

    trapperjohn MB Enthusiast

    Messages:
    7,316
    Joined:
    Nov 19, 2008
    Location:
    Lancashire
    Car:
    124 300D 24V Estate
    Have I missed something here? Is this the one you plan to run on WVO.

    Good Luck with it.

    CHEERS
     
  7. jaymanek

    jaymanek Authorised Forum Sponsor Authorised Forum Sponsor

    Messages:
    16,412
    Joined:
    Nov 29, 2002
    Location:
    Nuneaton Warwickshire
    Car:
    Lots of Mercedes!
    sorry i missed that, thought it was only one.
     
  8. Alex Crow

    Alex Crow Active Member

    Messages:
    278
    Joined:
    Sep 30, 2011
    Location:
    Super Suffolk
    Car:
    S210 320cdi
    under the cover behind the fuses is a small relay with a clearish plastic cover, could well be that at fault.
     
  9. Pontoneer

    Pontoneer Hardcore MB Enthusiast

    Messages:
    13,415
    Joined:
    Aug 19, 2002
    Location:
    Ayrshire
    Car:
    '99 S320 W140 ; '93 300SL-24 R129
    Yes , the E250D .

    I was thinking of running it on veg oil bought from supermarkets , but since that now costs almost as much as Diesel it seems hardly worth the bother .

    Not to hijack this thread any further , I will start a thread re the new car once I get it , hopefully within the next week or so .
     
  10. OP
    OP
    dinoy

    dinoy MB Enthusiast

    Messages:
    1,999
    Joined:
    Feb 15, 2010
    Location:
    london
    Car:
    mercedes of course
    ok more dignostics, took the replay out the windows do not work, it is intermentant, it effect seat presenter (radio), windows.

    once i disconnected the battery, the problem came back if that is any help, i do not know how it get back to working, obviously the soft top not working either.

    any clues are welcome
     
  11. grober

    grober MB Master

    Messages:
    27,851
    Joined:
    Jun 22, 2003
    Location:
    Perth, Scotland
    Car:
    W204 C200CDI Estate
    Sounds like the Convenience relay = the centrally positioned relay closest to the bulkhead in the engine compartment fuse box. Failing that check and clean all the fuses/ connectors in the fuse box--- after that its the convenience module [ expensive] under the rear nearside seat.
     
  12. OP
    OP
    dinoy

    dinoy MB Enthusiast

    Messages:
    1,999
    Joined:
    Feb 15, 2010
    Location:
    london
    Car:
    mercedes of course
    there is 2 different black modules which is it pls i will change the fuses as precaution too, and c
     
  13. grober

    grober MB Master

    Messages:
    27,851
    Joined:
    Jun 22, 2003
    Location:
    Perth, Scotland
    Car:
    W204 C200CDI Estate
    The beauty of the bayonet type fuses is that you can readily see if they are blown. If they are OK just give the ends and contacts a clean with abrasive= a fine woven nylon type pan scourer material [ detergent free] works well= non conducting particulates. Of the 2 units at the back the bigger one with multiple connections along one side is the convenience module the smaller unit [ underneath?? ] is the IR central locking unit irrc. there is also a solenoid valve for the pneumatics in there also.
     
    1 person likes this.
  14. Alex Crow

    Alex Crow Active Member

    Messages:
    278
    Joined:
    Sep 30, 2011
    Location:
    Super Suffolk
    Car:
    S210 320cdi

    neither, see post #8 for a description of it.
     
  15. grober

    grober MB Master

    Messages:
    27,851
    Joined:
    Jun 22, 2003
    Location:
    Perth, Scotland
    Car:
    W204 C200CDI Estate
    Are you confusing the convenience relay [ engine compartment fuse box] with the convenience module [under the rear seat] which is what I was referring to?
     
  16. Alex Crow

    Alex Crow Active Member

    Messages:
    278
    Joined:
    Sep 30, 2011
    Location:
    Super Suffolk
    Car:
    S210 320cdi
    no, i was describing the convenience relay, the poster was looking at 2x black relays (presumably bulb failure monitoring etc and indicator/rear demist etc relays) so was presumably on the hunt in the rear of the fuse box.

    yes it could possibly be the convenience control module if fitted (not on early cars), but that is far harder to get at and troubleshoot. the relay in the engine bay is there to ensure the windows are powered with either door open or ignition on, and the one under the back seat is not even fitted to early cars.
     
    1 person likes this.
  17. OP
    OP
    dinoy

    dinoy MB Enthusiast

    Messages:
    1,999
    Joined:
    Feb 15, 2010
    Location:
    london
    Car:
    mercedes of course
    cleaned fuses, and replaced ones which are damaged, the problem with roof not openning still their, light is on the soft top button, tombs not going up or down i guess needs resetting again for all or one of the modules under the back seat,

    there are 3 units under the back seat one on drivers side one in the middle and one on the passenger side.

    what are these for how do u reset them at all, to see if we are back to where i was with the roof working.

    again any help otherwise i need to start from scratch again to get soft top working
     
  18. grober

    grober MB Master

    Messages:
    27,851
    Joined:
    Jun 22, 2003
    Location:
    Perth, Scotland
    Car:
    W204 C200CDI Estate
    The one on the nearside [passenger side RHD] is the convenience module. The one in the centre is for the tombstones[rollover protection] the one on the offside [ driver RHD] is usually the central locking pump unit [ lots of vacuum pipes and in a foam case] sometimes the IR central locking module is beside it. The cabrio roof control is usually behind the offside [ driver RHD] rear trim side panel- they seem to be prone to corrosion damage from water leaks but are hidden from sight.They all talk to one another so a fault in one may mean the others won't work altho they are OK.
     
  19. OP
    OP
    dinoy

    dinoy MB Enthusiast

    Messages:
    1,999
    Joined:
    Feb 15, 2010
    Location:
    london
    Car:
    mercedes of course
    it need visit to nigel of NJS in brand hatch they do recondition the units and fix it by recommendation from another member 01474 706960
     
  20. pimpmyc250td

    pimpmyc250td Active Member

    Messages:
    83
    Joined:
    Apr 8, 2011
    Location:
    republic of mancunia
    Car:
    c250tdw202
    blown fuse does that, had it on a w124 recently, started when i replaced the radio...changed fuse resolved..
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.