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Replacing rear LED indicators W204

Discussion in 'Electrics, Vacuum, Ignition and ECU' started by coleyjf, Sep 13, 2019.

  1. coleyjf

    coleyjf Senior Member

    Messages:
    112
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    Joined:
    Dec 27, 2007
    Location:
    Leicestershire
    Your Mercedes:
    R107 300SL(1988 ) now sold, 2010 CD220 (W204) Sport Auto 2.1l
    Hi all

    I've a 2010 C220 CDi (sport) saloon

    The rear nearside indicator LED lamp has an intermittent fault, keeps failing ( rear indicator lamp fail alarm) then coming back up after the engine is switched off. The "fail safe" operates in that the rear lamp flashes instead of the indicator as it should.

    I've checked the various terminals in the cluster, however as I can't make it fail to order it's difficult to pinpoint!

    I've a feeling it's a problem on the actual LED circuit board but so far I've not taken the whole unit out to examine it as I thought I'd pursue an information search ( here :) ) first.

    Three questions:

    1: Is the LED unit possible to remove from the cluster ( as I've said I've not tried it yet)

    2: Is the actual LED indicator unit a separate part or must I change the whole cluster if it's past repair.

    3: I've tried fitting a normal indicator bulb in the bulb holder ( there is an empty space )and this works OK, however is there likely to be a problem using a tungsten bulb on one side?


    Hoping for the usual expert advice from you all :D

    Cheers



    Jim
     
  2. LostKiwi

    LostKiwi Senior Member

    Messages:
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    Joined:
    Aug 25, 2006
    Location:
    Midlands / Charente-Maritime
    Your Mercedes:
    '93 500SL-32, '01 W210 Estate E240, 02 R230 SL500 (Malcolm Spec), 04 Smart Roadster Coupe
    1. No
    2. It's a single unit I believe.
    3. No idea
     
  3. OP
    coleyjf

    coleyjf Senior Member

    Messages:
    112
    Likes Received:
    8
    Joined:
    Dec 27, 2007
    Location:
    Leicestershire
    Your Mercedes:
    R107 300SL(1988 ) now sold, 2010 CD220 (W204) Sport Auto 2.1l
    Thanks LostKiwi

    I thought that 2 was that, BUT I've now found the answer to my actual problem in another slightly different post.

    It's not the LED lamp itself but due to an apparently inherent fault/fault liability in C class MB's in the rear light cluster earth connection it leads to intermittent failure of rear lights and/or indicators. One poster suggests strapping the earth track of the bulb holder directly to earth ( solder a wire and screw under the cluster fixing bolt) which I've now done!

    This mod seems to have resolved the problem PLUS the rear lights seem to be brighter :D so I'm going to do the same to the RHS cluster as well.

    I just soldered a piece of reasonable sized wire to the earth track of the clip out lamp holder (scrape away some of the coating on the track and it solders quite easily), thread it through the bulb holder cluster and made a loop in the other end and fixed it under an extra nut and washer on the bolt which holds the rear light cluster in place, simples :D

    Apparently this faulty design ( the pin in the connector for the main earth return is too small?) has caused meltdown and possibly fires in some C class cars.

    Thanks
     

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