Mk2 wiring help needed

[Dedubyah]

I am getting towards the end of my engine rebuild on my new to me 850 and have installed a Pazon Altair and reg/rectifier however I never took the time to check all of the electrical functions prior to tearing it down, other than starting it. Firstly, the headlight and indicators weren't working and when I removed the rubber cover from the master switch, I found it only has 3 sets of terminals, which I read ,was only on the 1971. I have ordered a new switch but in the meantime have connected the power in (Blue/Brown) to the power out(White) but when I power the Blue/Yellow or Brown/Green, I see voltage when probed to the frame, also can anyone tell me which connectors fit where on the 3 way headlight toggle switch? Help appreciated, thanks.

 

[Lineslinger]

Take pictures during disassembly, of everything. That gives you some basic form of starting reference.

 

[L.A.B.]

I found it only has 3 sets of terminals,

To use the three terminal switch plug the blue/yellow onto terminal three with the brown/green.

also can anyone tell me which connectors fit where on the 3 way headlight toggle switch?

Should be a two position switch but connect blue/yellow to terminal four and blue to terminal eight.

Andover Norton - LIGHTING SWITCH 2 POSITION 34660 LU31780 (LUCAS) - 06.8024

LIGHTING SWITCH 2 POSITION 34660 LU31780 (LUCAS)

andover-norton.co.uk

 

[Dedubyah]

Thanks for that, with the blue/yellow on T3 I have power to the headlight terminals, the high beam light comes on, I have 5ohms from the headlight connector earth to the battery but no headlight (bulb lights directly from a battery). When I replace it with the blue/green, I have a tail light, the brake light works and when I probe to earth it shows voltage. Does this indicate a short to earth in the brown/green circuit? It hasn't blown a fuse. I have only a basic understanding of electrics so any help is appreciated.

 

[L.A.B.]

with the blue/yellow on T3 I have power to the headlight terminals, the high beam light comes on, I have 5ohms from the headlight connector earth to the battery but no headlight (bulb lights directly from a battery).

Sorry I don't quite understand that, you say the headlamp circuit works then you said it only works powered by a battery?

Brown/green powers the tail lamp, pilot light and instruments. The brake light should work from white on T2.

If it hasn't blown the fuse then it's probably not a short circuit but I'm not sure what the problem might be if there is one.

 

[Dedubyah]

I meant that the bulb is okay, I tested it with a battery. I have voltage to the two sprung contacts in the headlight connector and 5ohms resistance in the earth connected to it, but the headlight doesn't work. Perplexed as to why not

 

[marshg246]

I meant that the bulb is okay, I tested it with a battery. I have voltage to the two sprung contacts in the headlight connector and 5ohms resistance in the earth connected to it, but the headlight doesn't work. Perplexed as to why not

Do you have a ground wire connected to the headlight shell and to the headlight socket? If still positive ground, these will be red wires. There must be 0 ohms between the battery positive and headlight shell and battery positive and headlight socket ground. Which type of headlight socket do you have - post a picture!

 

[L.A.B.]

The headlamp shell connection is really a connection to ground (red) for the front direction indicators, it should not be considered a ground to the battery. If there are no direction indicators then the headlamp shell connection is redundant. The headlamp should have its own ground/red wire.

 

[Andy Higham]

There should be a good return wire from the headlight bulb to the battery and from the horn button to the battery.
These are both quite high current devices, the horn is also inductive. If they try to return through the steering head bearings, it will cause pitting of the races

 

[Andy Higham]

On mine the only intentional frame connection is the large battery cable to the starter motor fixing bolt. Every component is connected to a return cable. Due to the decision I made on the starter motor return, I'm using a negative earth, but it is of no consequence, I could make the engine cradle frame etc out of plastic and everything would work perfectly. Copper wire is designed to carry electricity, steel tube isn't

 

[L.A.B.]

and from the horn button to the battery.

The horn button doesn't connect to the battery ground. The horn button connects to the horn and the horn connects to ground '71-on.

 

[Andy Higham]

Then the horn needs a good return. Grounding the horn through the button was always the way bikes did it

 

[L.A.B.]

Then the horn needs a good return.

The horn should have its own red wire connection to the harness.

Andover Norton - HORN LINK LEAD (54959639) - 06.2087

HORN LINK LEAD (54959639)

andover-norton.co.uk

Grounding the horn through the button was always the way bikes did it

Obviously not. My T140 and T160 are the same, button connects to horn not ground.

 

[Andy Higham]

This is how I have wired my Commando, the high current circuits are protected by fused relays.

Norton Wiring by Sigma Projects, on Flickr

 

[Andy Higham]

I have used Royal Enfield switchgear, it has everything I need and is reasonably well laid out

 

[L.A.B.]

One thing you (everyone) should do is replace all the original single and double bullet connector sleeves especially the ones in the five way connector under the fuel tank as they become brittle over time. The latest type do not.

If necessary the five way block can be replaced with five doubles as there should be no internal connections between the circuits.

 

[marshg246]

The headlamp shell connection is really a connection to ground (red) for the front direction indicators, it should not be considered a ground to the battery. If there are no direction indicators then the headlamp shell connection is redundant. The headlamp should have its own ground/red wire.

Of course, but knowing what he has connected might help understand the connections. "5 ohms" to ground means there is no meaningful ground to the headlight bulb if he's measuring from the headlight socket ground connection to something he thinks is ground.

Unless I missed it, we don't know which type of headlight bulb socket he has - a picture could answer a few questions and make answers more direct.

When the headlight shell ground is connected to a red wire, it is a ground to the battery just as all other red wire grounds. Yes, the headlight bulb and actually the pilot light (if fitted) should have their own red wires even though in many cases the ground to the pilot light is redundant.

 

[Dedubyah]

It has the original BPF headlight connector. I've been seriously considering making a new loom with spade and Deutsch connectors but will try running my battery earth up to the headlight shell in the meantime, thanks

Dale

 

[marshg246]

It has the original BPF headlight connector. I've been seriously considering making a new loom with spade and Deutsch connectors but will try running my battery earth up to the headlight shell in the meantime, thanks

Dale

You should have a red wire in the headlight shell and it should connect to the copper connector on the socket. There must be 0 ohms between that connector and the positive of the battery. If you have 5 ohms there, you are measuring to a bad ground. If that ground is a red wire, then there is a bad connection in the red wires to the battery. Only the red wires should be considered a ground on a Norton - never the frame.

 

[Dedubyah]

Hi Greg, yes it has an earth wire to that connector which goes into a quad bullet connector, shared with the indicators.I probed that to the battery and 5 ohms resistance, I guess that's why the indicators don't work either.