Brake Light Always On

Discussion in 'Electrical' started by 72 xlch, Jun 3, 2010.

  1. 72 xlch

    72 xlch New Member

    I replaced the bulb, the switch. with a dmm can see the switch is working. I need to know how the brake light should be wired. unfortunately, the current wiring does not correspond with the manual because previous owner upgraded from drum to disc brakes and re-wired using black or blue colored wires. Any info or advice would be greatly appreciated. Thanks!
  2. cdn-bigfoot

    cdn-bigfoot Junior Member

    I would meter them out.


    Temporarily connect your tail light with an extra length of wire and either alligator clips or just twist the wires together. Turn on ignition and try.

    NEWHD74FAN Experienced Member Retired Moderators

    Common to both stop light circuits is the wiring from the fuse block (battery power source), and the single wiring going from that main harness routed under the fender above the rear tire to the brake light & license plate connections. Of course there is the brake light switch in the brake master cylinder up front, and there is a switch in the brake pedal or master cylinder area as well so you could have a parallel sneak current path, so the light is on all the time. Sticking or shorted switch due to water intrusion is common.

    Use the basic diagram as a guide...

    Last edited: Jun 5, 2010
  4. BlackG30

    BlackG30 Member

    Have you changed something in the brake lever, right hand control? I did it and a small rubber cap that protects the switch was torn. The light was laways on. A small repair of the rubber cap or replacement solves the issue.
  5. 72 xlch

    72 xlch New Member

    Thank you everyone for your help! In the process of troubleshooting this, lite socket wires pulled out, Also broke a battery box/regulator mount that had corroded from battery acid. I metered all wires, re-terminated all old connections. Went to a great harley salvage shop, got a new(er) bulb socket, new bat box mounts. Brake lite now operates properly!:guitar Thanks again for the help!