Where does my control unit attach to the Norton?

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Jul 24, 2006
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I have bought a new main wiring harness from Andover Norton, for my MK3, and the control unit wiring is not situated in the same place as before, and what I suspect was the original wiring. Before, it was located on the front part of the battery carrier.

On the new harness, for some reason, the wires for the the control unit exit the harness just in front of the rubber spindles on the main frame spine, where the head steady mounts.

The control unit has one lug, or mounting hole in it. So I would assume that there is some place that it is supposed to be mounted specifically? Obviously I can fit it in amongst the wiring bundles if necessary with a plastic tie, but wondered if anybody out there know where the designers intended this to be?

This wiring harness also had an extra blue/brown (I think it was) that went down towards the alternator area, so could it be for a foreign market, or possibly for an interpol?

The encapsulated warning light control unit normally fits onto the battery carrier.
Although some of the very early 850 MkIII's I think had the silver can item suspended from a spring that was fitted near head steady but didn't use so many wires.
Maybe they've had a batch made up using an old pattern harness copied by mistake?
The odd extra wire is to be expected and the Interpol models did have extra wiring.
The warning light unit on the MkIII should fit on a single screw fitted to the forward part of the battery carrier behind the air box. I changed my carrier when I fitted a 750 air box, but from memory there was a small alli spacer with a grub screw underneath together with an infernal serrated washer.

The quality of recent harnesses is questionable. I have heard a story that all the "genuine" items for years were made by one old chap who died suddenly a couple of years ago leaving the owners of the Green Globe trademark to find an alternative source. Apparently he had no "jigs" and made everything by eye.

Disclaimer:- This could be the Bike Rally / Five pints rumour mill at work and before Hewho points out the risk of legal action, I don't really want to suggest that the parts we buy are anything but "genuine."

* Just read L.A.B.'s post. I hadn't heard of the earlier assimilators on MkIIIs. In addition to Interplod wires, I seem to recall that the cables for an electronic tacho are there as well.

As an aside, does anyone know a source of the large size 90° "flag" type connectors originally fitted to the zeners ? Current looms have straight Lucars and I can't find any proper ones.
Thanks for the replies.

There is no obvious place to fix it to when taking into consideration the length of the wires. The unit wont quite reach the coil mounting cluster to attach there, and the wires leave the loom pointing forwards after the rubber bobbins as I said above. Also the correct number of wires are present.

It's not a big problem but I just wondered if anybody "knew" the intention of the wiring design, in relation to this control unit.

I think that you should give Nick Hopkins at BSA Regal a ring and ask him. If you still have the old loom and it has the 90° "flag" connectors for the two zeners then it is probably original (or at least 20years old).

You say that the correct wires are present. If it has the double red, white/brown, white/green, green/yellow and double white then I think that it has to be for the MkIII assimilator. The earlier versions mounted off a spring on the coil bracket but had IIRC only two wires.

Good luck and let us know what you find out.
I have indeed given Nick Hopkins a ring, and as usual he was most helpful.

Apparently my wiring harness has been manufactured incorrectly! The wires shouldn't be there, they should be as original, going to the front of the battery tray area. So that is that as they say.

The earlier sprung device that L.A.B. mentions was a switched device, and for this reason was on a spring, whereas the later type are solid state, so there are no issues with leaving mine there unsprung.

My new wiring harness also came with straight connectors for the zener diodes. If you 79x100 do find out where I can get some flag type connectors, let me know please, and I may well fit them retrospectively.
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