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Headlight Switch Question

Discussion in 'Audi S4/A4/A4 Cab (B7 Chassis)' started by DTM_T4, Sep 26, 2012.

  1. DTM_T4
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    DTM_T4 New Member

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    Did a search trying to answer this but couldnt find anything usefull.

    I am trying to retrofit front foglights to my DTM and went to try the install tonight. I have got a genuine loom and a new headlight switch with the auto function and both front and rear fog positions part number- 8E0941531b (DTM switch only has rear posistion on the switch).

    I fitted the loom and the new switch and turned the car on two clicks on the key and the main beam came on straight away even though the switch was in the 'O' posistion and stayed on untill I removed the key. When the switch is in the auto posistion the headlights came on (was dark at this point) and went off when the key was turned to the posistion where you can remove it as it should. When the switch is turned to the sidelight posistion the main beam stays on and the symbol on the switch stayes red. When the switch is in the main beam position the main beam is on but the dis throws up a numberplate bulb out warning (both bulbs are on though). The fogs work both front and rear as they should do with the switch in each position.

    When I refitted my original headlight switch all went back to working as it should with the exception of the front fogs came on as well as the rears when the switch was pulled out to the rear fog posistion.

    I tried coding the 'Fog Light Cold Diagnosis' to '0' in channel 16 in central electrics using VCDS but it didnt change anything.

    So my question is does anyone have a wiring diagram for this new switch or the plug that goes into it, or can show me pics of how their switch is wired?

    Any help would be greatly appreciated.
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  2. Gazthesparky
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    Gazthesparky Member

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    I'm guessing that the two switches are wired differently so you should check the differences between the 2 wiring diagrams

    I have no personal experience of this it's just something that I've read other users on here have done and that's if you disconnect the switch the lights come on permently as standard as a safety precaution. Which to me suggests a wiring difference between the 2 switches.
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  3. DTM_T4
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    DTM_T4 New Member

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    Does anybody have a wiring diagram for this switch or know where I can find one???
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  4. bez101
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    bez101 Yorkshire & Humber Rep. Regional Rep

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    did you already have auto lights ?
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  5. DTM_T4
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    DTM_T4 New Member

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    Yea, already had auto lights, only thing that's different is the front fog position on the new switch.
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  6. bez101
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    bez101 Yorkshire & Humber Rep. Regional Rep

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    strange
    last DTM i added fogs was plug and play with the correct loom
    all i needed to do was activate the fogs
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  7. DTM_T4
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    DTM_T4 New Member

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    Did you change the switch for one with two positions for front and rear fogs? My original switch would work, it just operates both front and rear fogs at the same time as it only pulls out once. Just not sure how MOT legal that is :S
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  8. bez101
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    bez101 Yorkshire & Humber Rep. Regional Rep

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    yeah changed that i got q from a B7 on same year
    i know sometimes that light switch is diffrent
    what was yours from
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  9. DTM_T4
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    DTM_T4 New Member

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    My cars a 55 plate but not sure what year the replacement switch is from. All the eBay ad said was that it was from a B7 RS4. Part number reads:-
    8E0 941 531 B 01B - K07740 BK7.
    If that tells you anything?
    #9

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