1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

W211 main beam always on

Discussion in 'Electrics, Vacuum, Ignition and ECU' started by Mackc, Jun 27, 2019.

Tags:
  1. Mackc

    Mackc New Member

    Messages:
    3
    Likes Received:
    0
    Joined:
    Jun 27, 2019
    Your Mercedes:
    W211 E Class 2005 E500
    This is my first post... nice to be here and hope to receive some pointers from those with oilier hands and wiser heads than me.

    My 2005 w211 E500 main (high) beam is stuck always on, even without the key in so i’ve had to disconnect the bulb to stop it flattening battery and annoying oncoming drivers. It’s the high beam in the inner light cluster.

    The headlight selector dial position doesn’t make a difference and the indicator stalk isn’t in the park light position. There are no error codes. It’s got factory xenons.

    I thought it might be a faulty earth, so cut the cable and made a new earth. This appeared to fix the problem, but after a couple of months it’s doing it again.

    Any advice as to what to try, testing methods, or even what to rule out? I’m thinking bulb holder, wiring, controller module, light switch, indicator stalk etc are all possible which is a bit overwhelming.

    Thanks in advance,
    Mack
     
  2. OP
    Mackc

    Mackc New Member

    Messages:
    3
    Likes Received:
    0
    Joined:
    Jun 27, 2019
    Your Mercedes:
    W211 E Class 2005 E500
    Forgot to say it’s only on the drivers side (uk car) and all other lights work fine
     
  3. Oldspanners

    Oldspanners Senior Member

    Messages:
    523
    Likes Received:
    338
    Joined:
    Oct 30, 2017
    Location:
    Normandy
    Your Mercedes:
    C CLASS 2004 C180
    I'd be looking at the earthing of the light and the cable you repaired as that fixed it the first time.
     
    LostKiwi likes this.
  4. OP
    Mackc

    Mackc New Member

    Messages:
    3
    Likes Received:
    0
    Joined:
    Jun 27, 2019
    Your Mercedes:
    W211 E Class 2005 E500
    Hi OldSpanners,
    Thanks for your suggestion... I checked the earthing and I think it's ok.
    The problem's changed a bit.
    The inner light is still always on full beam, but now with the main headlight on the same side, the high beam doesn't work at all.
    Also, I noticed when I flash the headlights, I can hear a clicking in the working headlight, but no clicking on the non-working headlight.
    What is it that clicks? The ballast, an ignitor, or is there a relay somewhere? I'm guessing both sides should click?
    I've just tried changing the ballast on the non-working side, but it hasn't made any difference.
    any advice and pointers would be really appreciated...
     
    Last edited: Jul 13, 2019
  5. Oldspanners

    Oldspanners Senior Member

    Messages:
    523
    Likes Received:
    338
    Joined:
    Oct 30, 2017
    Location:
    Normandy
    Your Mercedes:
    C CLASS 2004 C180
    Here's a link to the wiring diagrams for a 2005 E500 from a USA site click on the links on the bottom of the page to pull up the diagrams. They may give you a common point to check through. I am not familiar with the Xenon system but you may have some live wire melted into the headlamp circuit giving you the fault.
    http://www.bbbind.com/tsb-wiring-diagrams-database/
    Sorry link doesn't bring you direct to the diagram but click on "wiring diagrams" fill in the drop down menus and you'll get there.
    P.S. You need to use "reply" to the post otherwise no one will get a notification you have replied.
    E1e1, High beam and E1e8 Low beam Xenon headlamp seem to be controlled by the same module which is switched though a 4 way connector and then a 2 way in the headlamp. Maybe worth looking at.
     
    Last edited: Jul 13, 2019
  6. Oldspanners

    Oldspanners Senior Member

    Messages:
    523
    Likes Received:
    338
    Joined:
    Oct 30, 2017
    Location:
    Normandy
    Your Mercedes:
    C CLASS 2004 C180
    Had a look at the wiring diagram (if it's the same for your car) there is a 4 way connector to the lamp.
    Terminal 1 is the earth coming from the "wheel housing" on that side, 2 is the low beam, Xenon control and ignition module which seems to have a separate connector inside the lamp, 3 is the side light and 4 is the high beam.
    The wires from 2,3,4 all go to the illumination control module (terminals 5,19,6) on some models via another headlamp harness connector. Unless all three are in contact with a power source which will light all three lights the problem looks likely to be the illumination control module.
    Hope this is of some help.
     
    Last edited: Jul 14, 2019 at 10:47 AM

Share This Page