Brake light issue

Discussion in '1947-1954' started by Mr-Pico, Aug 16, 2014.

  1. Mr-Pico

    Mr-Pico Member

    Joined:
    Aug 12, 2014
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    Location:
    Vallejo Ca
    Ive searched and cannot find the answer to this, so Im hoping someone can help me out.
    54 Chevy 3100, New Headlight Switch, Stoplight Switch and Dimmer Switch.
    With the lights off, Brake and turn signal lights work perfectly.
    With the park lamps on or headlights on..tail lamps and signal work, but no brake lights.
    I checked for power at the brake light switch and there is power only when the pedal is applied and headlamp switch is off . With the headlights on there is constant power at the switch...is this supposed to be this way?
    Any suggestions as where to start aside from completely rewiring the truck
    Any input would be appreciated.
    Thanks
    Roger
     
  2. Tubby

    Tubby Member

    Joined:
    Oct 12, 2012
    Messages:
    100
    [​IMG]


    Almost sounds like your stop lamp is wired to the wrong post.

    But you say it they don't work the park lamps on
    Or the head lamps on.

    When the headlamps come on the power is off to the park lamp post on the switch.


    That's one things to check. Make sure it's on the correct post.

    Hopefully others will have ideas for you.
     
  3. coilover

    coilover Member

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    Location:
    Plano US
    One side of the brake light switch (BLS) is always hot. The brake lights worked on these old trucks with NO other switch on and were often known to run the battery down if the pedal did not return to the complete up position. You can check by leaving the wire back to the lights on one BLS terminal and running a jumper from the other terminal to the "BAT" terminal on the voltage regulator or any constant hot source.
     
  4. morabuffalo

    morabuffalo Member

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    Albuquerque, NM
     
  5. Mr-Pico

    Mr-Pico Member

    Joined:
    Aug 12, 2014
    Messages:
    23
    Location:
    Vallejo Ca
    Thanks Tubby for the light switch picture, I was able to use it as a reference and traced each wire back to the correct position.

    Thanks Coilover, we noticed that the fuse block under the hood had one hot wire connected to nothing, after finding a diagram online late last night we found it was supposed to be for tailights...who ever wired this truck before was either real lazy, drunk or both.

    morabuffalo... doing electrical is on my list of hates :D
     

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