I have already covered in an article here about the Lucas Master Switch (ignition key switch) and how to connect it.
This article covers the difference between the standard ignition key switch and the one that was used for the Canadian market.
On the MK3, this switch sits along side a ”headlamp warning unit” in lieu of the ”warning light assimilator” that allowed the bike to meet Canadian law.
In 1972 Lucas moved to the 4 position key switch, which was used right the way through to the end of production.
The MK3 Commando saw a minor modification to the switch, but it was only to the bezel, so that it sat better in the little dashboard/instrument panel.
The back of the key switches are the same, and look like the following.
However, there was a difference in the MK3 switch that was used for the Canadian market, as it was made legislation that a vehicles lights must be on while the vehicle’s engine is running.
To that end, with the Canadian switch, the pilot light, instrument (tacho and speedo) backlights and tail light would be lit up when the ignition key was all positions other than off.
So the fundamental difference with the British and Rest of World switch was the pilot lights being on in the “Ignition Only” position.
England and Rest of World
- Lucas Part Number: LU30552
- Norton Part Number: 066395
On the Standard “Rest of World” switch – Pin 3 NG (Brown/Green) is open when the Key is in the “Ignition Only” position.
- Lucas Part Number: LU30825
- Norton Part Number: 066625
On the Modified “Canadian Market” switch – Pin 3 NG (brown/Green) is shorted with both Pin 1 NU (Brown/Blue) and Pin 2 W (White) when the Key is in the first “Ignition and Lights” position.