Tail light not working

Discussion in 'Airheads' started by sh1bby69, Oct 6, 2012.

  1. sh1bby69

    sh1bby69 Been here awhile

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    Aug 17, 2010
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    670
    Location:
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    So I picked up a Boxer Metal rear fender eliminator. I sent out and powder coated and now it won't work. I'm thinking it has to do with grounding it but I'm not sure what to do. Do I have to expose some metal to get the tail light to work?
    #1
  2. Boxer Metal

    Boxer Metal Mad Scientist

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    3,611
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    Chico, California
    The brown wire from the tail light harness need to be hooked up to one of the threaded studs on the back of the tail light and all will be well.
    #2
  3. sh1bby69

    sh1bby69 Been here awhile

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    Thanks!!

    Sent from my Galaxy Nexus using Tapatalk 2
    #3
  4. canehdian_guy

    canehdian_guy Adventurer

    Joined:
    Jul 31, 2013
    Oddometer:
    66
    Does anyone know why my tail light wouldnt be working although my brake lights still work?

    My day time running lights and high beam are still functional and my fuses all seem fine.

    Thanks
    #4
  5. CafeDude

    CafeDude Ride to eat.....

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    Bad bulb?
    #5
  6. east high

    east high Long timer Supporter

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    The Lost Coast, CA
    It's usually this. It's a dual filament bulb.
    #6
  7. pietas

    pietas Been here awhile

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    If it is not the bulb, check the wiring and switches. Buy a new bulb to make double sure of this
    If neither the front nor back brakes activate the brake light, check the brake light loom as well as the connector block between the looms. Use switch cleaner to clean the connectors and switches

    Get a colour coded wiring diagram to understand which wire goes where
    Use a multi-meter to check for connectivity on wires and switches

    I had the same issue last year. Mine was a dirty connector but the loom can just be old
    #7
  8. deafanddiabetic

    deafanddiabetic Would rather be wrenching.

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    There's already great advice here, but we don't know which model is your bike.

    If it's a /5 or /6, the tail running light is run off of the grey/violet wire in the headlight bucket.

    It's likely the bulb though, it gets me every time!:huh
    #8
  9. ewilly

    ewilly Been here awhile

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    I need to jump in on this one!

    My issue is the brake light is working but no running light at rear or gauge lights. I put knew rear light on rear when I changed fenders and have not had power past the rear connector since.

    Popped Relay?
    Looks like the fuses in bucket are good!

    Ideas.


    Hope I am not hijacking to bad.
    #9
  10. deafanddiabetic

    deafanddiabetic Would rather be wrenching.

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    Have you physically tested the rear sub harness with a voltmeter to see if power is actually going to the bulb socket?

    Again, depending on what model you have the tail light and gauge lights are on in "park" mode as well as run. My rear lights are run from my light relay by a grey/violet wire. But if I had it plugged into the wrong post I'd lose my running light/gauge lights but my brake lights did work. If yours started only after you changed your tail light to something else, start with the bulb and if not there, check the wiring again.
    #10
  11. Prmurat

    Prmurat Long timer

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    No ground with the powder coat paint?


    Sent from my iPhone using Tapatalk
    #11
  12. Warin

    Warin Retired

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    The gauge lights and rear running light (tail light) usually run off the same circuit... Got head lights?

    Not likely to all those bulbs blown at once, nor ist it likely to be the ground.. So look at where the power gets switched to those lights .. handle bar switch?

    Which model and year of bike?
    #12
  13. ewilly

    ewilly Been here awhile

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    Yes got head lights and no power for tail at harness connector under seat.

    It is an 84 r100
    #13
  14. Warin

    Warin Retired

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    Pull out your wiring diagram.

    There is a switch that turns on your lights (headlight/tail light) .. on the left handle bar ..

    You want the wire from that that runs off to the tail light (and gauge lights) .. it goes to your headlight bucket .. that is where you want to test ..

    Is there power coming out of the switch ? No .. And the headlight works .. that means there is power to the switch .. so then probably the switch ...

    If power comes out of the switch then there is a connector from there to the gauge lights and the rear tail light .. check there.
    #14
  15. canehdian_guy

    canehdian_guy Adventurer

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    Oddometer:
    66
    Refresh: my running tail light is not working, but my brake lights, headlight and gauge lights are working.

    I have a color diagram in front of me, but I'm having trouble making sense of this.

    In the diagram there are three wires leading to the tail/brake light: one is the ground wire, another is connected to the front/rear brake switch, and the last one connects to the ignition switch.


    Where should I start? Would it be a connection prior to the ignition switch? Because that's all I could think of.

    Thanks
    #15
  16. Warin

    Warin Retired

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    19,008
    Brown in color .. that one works (as demonstrated by the stop light working) [we hope .. if the 'stop light is dim' .. and the instrument lights come dimmly on then this wire/connection is NOT working]
    Brake light supply. Working - as the brake works.
    That is the one to check. Does the ignition switch connection also go off to the instrument lights? It is does and they work .. then the ignition switch is working, if not then you need to check for power (voltage) on that switch connection , and while your are there that the wire is actually connected. If you have power there then;

    • bulb connection not working correctly
    • connector between bulb and switch faulty - check pins/sockets are not forced out of the connector.
    • Wire frayed under steering head
    #16
  17. motu

    motu Loose Pre Unit

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    Been through this today. Yesterday I found my tail light wasn't working, it's winter here and riding in fog and rain so not good. The grey wire was off the ign switch. They are soldered on, and I fitted Polly Heaters a couple of weeks ago, I had to remove the instrument panel to fit the switch and the wire must've broken then. How long did I have no light? I cut back and re soldered the lot.
    #17
  18. Runaway Train

    Runaway Train The Left-Right Tourer

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    I had the same problem. Twice actually except it was blowing fuses. It turned out to be the flimsy brass bulb sockets in the clock voltmeter. Each time the grey wire has come unsheathed and was grounding on the socket. Perhaps your sockets aren't grounding well?
    Just a thought and it's easy to check.
    #18
  19. canehdian_guy

    canehdian_guy Adventurer

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    Oddometer:
    66
    Cool thanks guys. I'll have a look.
    #19