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Boyer trouble

Discussion in 'Norton Commando Motorcycles (Classic)' started by seattle##gs, Mar 26, 2019.

  1. seattle##gs

    seattle##gs

    Joined:
    Oct 28, 2014
    I have a Boyer black box...the power wire from the harness going to the white wire on the Boyer box reads 12.5 volts. As soon as I connect the white wire it drops to 2.4 volts. Why? No spark.
     
  2. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    Maybe high resistance somewhere between the battery and your “power wire?”

    Try a connecting a test jumper lead direct from the battery live terminal, to the Boyer.


    Suspect the kill switch, fuse holder, key switch.
     
    concours likes this.
  3. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    Or a failing battery.
     
  4. seattle##gs

    seattle##gs

    Joined:
    Oct 28, 2014
    Here's a new one.....The hot wire I was using, white/brown, reads 12.5 but no spark. If I run a jumper to the - battery terminal I get a good spark. For some reason the hot wire is unusable. Why?
     
  5. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    Sounds like it’s not the battery, which is good news.
     
  6. kommando

    kommando

    Joined:
    May 7, 2005
    If the wire is broken internally except for a couple of strands you get full voltage but no amps.
     
  7. Supercat

    Supercat

    Joined:
    Aug 23, 2017
    Good advice so far, and it sounds like you're well on your way to having this sorted. Just to add 2 cents to the conversation - voltage loss is caused by: "poor connections, bad contacts, insulation problems, or damaged conductors".
     
  8. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    Triton Thrasher had provided the most likely devices at fault. Look there first.
     
    Supercat likes this.
  9. bill

    bill

    Joined:
    Jun 1, 2003
    the white with brown is from the bulb for the ign warning light. if wired correctly a white ( key on ) goes to the bulb and the w/b is grounded buy the assimalator to light the bulb. with the bulb in the circuit it was a resistor and i am surprised you did not burn out the bulb. the kill switch should have a white / yellow to the boyer and a white to the kill switch if you are going to use it.
     
  10. seattle##gs

    seattle##gs

    Joined:
    Oct 28, 2014
    I could find no other hot wire to work with. Usually it is a white/yellow or white but nothing showed 12V. I found a s spare tab on the key switch so I used that.
     
  11. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    White/brown* is certainly the wrong wire to connect the ignition to, as Bill said.
    Any white should certainly show battery volts and also white/yellow if the kill switch is connected and working so how did you test for volts?

    *Edit: This is assuming it's your Mk2A Commando and not something else?
     
    Last edited: Apr 1, 2019
  12. seattle##gs

    seattle##gs

    Joined:
    Oct 28, 2014
    It is someone else's Norton. I used a meter to find a hot wire.
     
  13. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    You used a meter, but found a rather tepid wire.
     
  14. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
  15. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    So, what "Norton" is it?

    If it's not a '71-on Commando then we need to know what it is as white/brown wil not be the charge warning bulb-to-assimilator wire.
     
  16. bill

    bill

    Joined:
    Jun 1, 2003
    how about you spend a little time studying a wiring schematic for the year you are working on. if you did you would not be chasing your tail and asking these questions.

     

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