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  • Headlight & Clock Lights inop

    The good news is, I replaced the cam chain, valve shims, added an auto CCT, and it started right up and runs fine!

    The bad news is, the headlight won't turn on, bright or dim. The speedo and tach are dark too.

    I disconnected the RLU, and I have no voltage on the black wire, or any other pin. I should tell you here that I replaced the main wiring harness while I was doing everything else.

    I gave it a little RPM and saw 13.5V come up across the battery. I checked all of the fuses. Signals, taillight, plate light, flashers, all function. I checked all of the connectors behind the fuse box. I'm tired and hoping I missed something obvious.

    I have an unused connector in the headlight shell that has two red wires on it. I believe it goes live when I turn the key on. I have another unused one with two blue wires on it. Those connectors are shown unused on the wiring print.
    Marty (in Mississippi)
    XS1100SG
    XS650SK
    XS650SH
    XS650G
    XS6502F
    XS650E

  • #2
    Marty, your headlight relay isn't pulling in. It gets power from one of the white alternator wires though a diode when the motor starts. Check for voltage at the relay, if the diode has failed it won't work.
    Fast, Cheap, Reliable... Pick any two

    '78E original owner - resto project
    '78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
    '82 XJ rebuild project
    '80SG restified, red SOLD
    '79F parts...
    '81H more parts...

    Other current bikes:
    '93 XL1200 Anniversary Sportster 85RWHP
    '86 XL883/1200 Chopper
    '82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
    Cage: '13 Mustang GT/CS with a few 'custom' touches
    Yep, can't leave nuthin' alone...

    Comment


    • #3
      You can temporarily bypass the headlight relay to see if everything works. Unplug it and jump the red/yel and blu/blk in the harness connector. Everything should light up with the key on. You might have a bad diode in your harness (80-81 only) that operates the headlight relay.
      2H7 (79)
      3H3

      "If it ain't broke, modify it"

      Comment


      • #4
        Steve,

        I'm not looking at the print, but is that relay supposed to get voltage with the key on, before the engine starts?
        Marty (in Mississippi)
        XS1100SG
        XS650SK
        XS650SH
        XS650G
        XS6502F
        XS650E

        Comment


        • #5
          OK Phil, I can jumper out the RLU and T/S with just the battery. Thanx.
          Marty (in Mississippi)
          XS1100SG
          XS650SK
          XS650SH
          XS650G
          XS6502F
          XS650E

          Comment


          • #6
            Originally posted by jetmechmarty View Post
            Steve,

            I'm not looking at the print, but is that relay supposed to get voltage with the key on, before the engine starts?
            Nope, it doesn't power up until the motor starts and the charging system has output. Theory is to reduce the battery load for starting....
            Fast, Cheap, Reliable... Pick any two

            '78E original owner - resto project
            '78E ???? owner - Modder project FJ forks, 4-piston calipers F/R, 160/80-16 rear tire
            '82 XJ rebuild project
            '80SG restified, red SOLD
            '79F parts...
            '81H more parts...

            Other current bikes:
            '93 XL1200 Anniversary Sportster 85RWHP
            '86 XL883/1200 Chopper
            '82 XL1000 w/1450cc Buell, Baker 6-speed, in-progress project
            Cage: '13 Mustang GT/CS with a few 'custom' touches
            Yep, can't leave nuthin' alone...

            Comment


            • #7
              Can you guys tell where in the harness that diode is hiding?
              Marty (in Mississippi)
              XS1100SG
              XS650SK
              XS650SH
              XS650G
              XS6502F
              XS650E

              Comment


              • #8
                http://www.xs11.com/forum/showthread...threadid=17963
                2H7 (79)
                3H3

                "If it ain't broke, modify it"

                Comment


                • #9
                  Yep. It's the diode. Thanks guys.
                  Marty (in Mississippi)
                  XS1100SG
                  XS650SK
                  XS650SH
                  XS650G
                  XS6502F
                  XS650E

                  Comment

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