This is as per the Power Arc electronic ignition diagram I have detailed in the post prior to this, which can be FOUND HERE.

However, these diagrams have been amended to accommodate the MC2 dual output single coil that is sold in the Old Britts kit.

1968 Norton Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil

These are the pre-1971 bikes and have the ammeter in the headlight shell, as well as the Wipac Triconsul type handlebar switch.

The wiring is very simple, and more like the Atlas than what came to be familiar with the Commando.

Note that I have included the Front Brake Switch as standard – this was a US requirement, that didn’t appear on the earliest UK bikes.

1968 Norton Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil PNG 5600×3960

This diagram is also downloadable as a PDF from HERE

1971 Norton Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil

This is often referred to as the “Interim” model.

It is distinguishable by the three pin master switch (ignition key switch) which was Lucas part number LU39565.

These were made ONLY for the Norton Commando, and are no available as an aftermarket replacement.

If you are not comfortable rebuilding the switch, most people choose to go for the LU30552, which IS readily available.

You can find an article on ignition switches here, that may be of interest.

1971 Norton Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil PNG 5600×3960

This diagram is also downloadable as a PDF from HERE

1972 onwards Norton Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil

The 1972 onwards schematic covers 750 and 850 bikes and has the much more familiar four pin master switch (ignition key switch)

1972 onwards Norton Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil PNG 5600×3960

This diagram is also downloadable as a PDF from HERE

MK3 Commando

During the manufacture of the MK3, Norton and Triumph were coming together, and they were often feeding from the same parts bins.

We have noted some anomalies between the handlebar switches while the MK3 was in production, as they frequently used the Triumph T140E switches, which look the same, but have a couple of small wiring differences.

Left handlebar switch the U (blue) used by Norton (and illustrated in the factory workshop manual) has been replaced with a UY (blue/yellow) cable. This connects to the U (blue) of the right handlebar switch inside the headlamp bucket.

Right handlebar switch there is no S (slate grey) instead, the single “hot” negative from the pin 2 of the Master Switch (ignition key switch) is jumpered for both engine run/kill switch and the starter button.

Another element of the MK3 that sometimes causes confusion is the wiring around the Warning lights.

The factory workshop manual shows the following:

I have covered this in more detail in a separate article, which can be found here.

But in short, the cable colors used for the sub-console wiring harness were not the same all the way through MK3 production – so certainly something to watch out for!

1974 Norton MK3 Commando (Early) Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil

1974 MK3 Early Bikes – there were around 2,000 bikes that were built around the December 1974 timeframe that have three additional fuses that can be found in the headlamp bucket.

These bikes are also wired with the old Lucas 3AW 3 wire ‘silver can’ assimilator.

1974 Norton MK3 Commando (Early) Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil PNG 5600×3960

This diagram is also downloadable as a PDF from HERE

1975 Norton MK3 Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil

This is the most common configuration, and takes us through to the final Commando that rolls off the production line.

1975 Norton MK3 Commando Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil PNG 5600×3960

This diagram is also downloadable as a PDF from HERE

1975 Norton MK3 Commando (Canadian Market) Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil

For the Canadian Market, there were legal requirements around the headlamp being on while the engine was running.

The wiring diagram includes changes needed (swapping out the Warning Light Assimilator 06-6393 for the Headlamp Warning Unit 06-6392).

Note that a different Master Switch (ignition key switch) is also required – the key switch differences for Canada are covered here in a separate article.

This is covered in the Factory Wiring Diagram, by notes.

While the Headlamp Warning Unit is available from our friends at Andover Norton, the Canadian key switch LU30825 is not available, and must be rebuilt manually.

1975 Norton MK3 Commando (Canadian Market) Wiring Schematic + Power Arc Electronic Ignition AND MC2 Coil PNG 5600×3960

This diagram is also downloadable as a PDF from HERE

NOTE:

A couple of points about the way these diagrams have been drawn: