kill wire hook-up?

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Feb 20, 2008
I am putting a japanese throttle with a built in kill switch wire. My question is should it go to the ignition switch(the long way) or run it to the negative bracket on the coil.(positive ground)
The kill switch needs to be a two wire type. One wire connects to the ignition switch (White wire) power circuit and the other should go to the ballast resistor ('71-on models) and then to the coils from the ballast resistor (if it has points ignition?).

A single wire kill switch (grounding switch) won't work, if that is what you have? As the ignition circuit runs off the battery, so the switch needs to be the type that interrupts the power supply to the coils when it's pressed or set to OFF. A ground switch (if connected to the power supply) will cause a short circuit.
If you have a push to ground switch, you could make it work with a relay. You wire the relay so the push to ground completes the primary side and opens the normally closed secondary side of the relay.

Les, I'm a little electrically challenged. Your description, I think is for a push to open button like the late Commando button. On P11's we have a two wire button that is push to close and points and coil. Any idea how this gets wired? My thought was to wire it as I described using a relay, but it wasn't wired that way originally. With battery and coils, it seems that any grounding of the coils will blow the fuse.

I have period Lucas wiring diagrams, but they don't show a kill button and I don't think Norton (or Matchless) ever published a wiring diagram for P11.

Any ideas?
Ron L said:
On P11's we have a two wire button that is push to close and points and coil. Any idea how this gets wired?


I'm not sure about that, at all.

Could that "push to close" switch also be a ground switch that connects both wires together when the switch is pressed and simultaneously grounds the two wires?
If so, a similar switch that contacts both "coil to points" wires and grounds them both together is found in the coils model Dominator wiring diagram.

If it's just a simple two wire push to close switch, then I have a diagram that shows that type of kill switch was used with the Lucas twin cylinder "Energy Transfer" (ET) ignition systems. As a wire running from each of the two ET coil primary circuits connects to either side of the switch? When the switch is pressed the two primary (AC) circuits become connected, which presumably shorts the AC and kills the sparks.
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