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Wiring confusion - 1972

Discussion in 'Norton Commando Motorcycles (Classic)' started by BrianG, Nov 3, 2017.

  1. BrianG


    Sep 4, 2009
    right above the carbs there is a main harness tap that throws 3 red (gnd) wires to one ring connector that goes to the head steady, and it also throws 2 white/red wires.

    I cannot even find white/red wires on the '72/'73 wiring diagram.. Any ideas what these are for?

    Also, at the front of the main harness, there are quite a number of black/white and black/yellow wires, some terminating in bullet connectors and some in female spade connectors.

    This bike has an early Boyer ign. installed so I suspect that these are related to the OEM points ign. ? My wiring diagram does not show wire colors past the ballast resistor. Can I presume that it is safe to ignore these wires? (I do not find them to be powered at any position of the ignition switch)
  2. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Nov 20, 2004
    White/red is the unused electric start push button-to-solenoid wire (so the wire will be live/hot when the button is pressed), as the factory intended to fit a Lucas electric starter from 1971, however, it proved unreliable so the Commando didn't get an electric starter (Prestolite) until the 850 Mk3.

    Correct, the black/white and black/yellow are the unmarked original points/condenser wires on the wiring diagram.

    The unmarked ballast resistor-to-coils wire was normally white/purple.
    Last edited: Nov 3, 2017
    BrianG likes this.
  3. BrianG


    Sep 4, 2009