Wiring 1966 T120

[gofer]

Can anyone owning a 1966 T120 assist with a wiring problem
The Zener has a white wire attached, which according to the Triumph manual connects to the rectifier. The only problem is that the manual indicates that this wire ends up as brown/white at the rectifier. This fault occurs on several wiring diagrams for various Triumphs from 1963-1970.
The solid state rectifier has four lugs. 2 to the alternator, 1 to earth, but what colour is the last wire. The manual shows a double brown/white lead from the rectifier to both the ignition switch and the zener
Have a new harness and only one female blade can attatch to the zener because it is larger than all the other blades and is white.
Additionally can anyone tell me the wiring colours that should be attatched to the ignition switch, I don't mean as read in the manual.

Appreciate all assistance in this frustrating matter, additionally invite all wiring experts to give me their feed-back.

Norway doesn't seem to have any competance when it comes to wiring and veteran bikes.

Gordon
1966 T120
(Norway)

[L.A.B.]

I don't own a 1966 T120 but I'm sure we can work through this little problem.

First, which of the wiring diagrams that you have matches the electrical layout of your bike/harness the nearest?
I would guess possibly the eng No. DU24875 with separate headlamp drawing?

If we are all looking at the same diagram then hopefully we can both understand what the other is describing.

If you need to refer to another diagram please say which one.

Do you have a multi test meter to use as a circuit tester?

If not then you could make a circuit tester from a battery,  a bulb and a few lengths of wire, then at least it is possible to find what wires are connected and where they go to, and can also help identify any switch connections.

The white wire with the large female spade most likely connects to the Zener. That wire should then connect to the rectifier Neg. terminal but could possibly join other wires (this is where a circuit tester comes in handy).

Are there any brown/white wires (or brown/blue?).

What is the wire colour that connects from the harness to the battery negative (ring terminal?).

And please try to answer all questions that are asked. As I can only go by what you can tell me, if you are not sure of anything then please say so.

If you want to continue with this 'off board' then please do?    
  

[gofer]

Thanks yr reply.
The diagram you are using is correct from DU24875 (home) with separate headlamp.
I use a multi test meter.
Zener wire (white) is correct. this leads to a double white crimped spade connector where one end goes to ....?.... (the book shows a double crimped brown/white spade connector at the rectifier) the other wires at the rectifier are correct.
This is where it gets confusing, since white wire from the zener should have gone (I think) to the rectifier, but the ignition switch shows a brown/white to the last spade connector on the rectifier.
The battery terminal lead is brown/blue.
Off-line address is gofer@online.no
Thanks

Gordon

[L.A.B.]

You have a test meter, *good* that makes everything so much easier and if any wires are not the colours that are shown in the diagram then it isn't such a problem.

So, check the continuity of the white Zener connector with any other white wire connectors.

As you have said the Zener wire goes to a double wire connector, that is most likely to be the rectifier Neg. terminal connector.

Where does the other end of the double wire go?

I would guess from the diagram that it goes toward the ignition switch?

I assume the ignition switch just a simple OFF/ON switch as shown in the wiring diagram.

So the brown/blue battery wire should go to the ammeter, and then to the horn, then horn switch.

The wire leading from the other side of the ammeter is shown as brown/white, is that what you have?
And does that wire go to the ignition switch?

The wiring from the Zener and rectifier should to connect with the wire leading from the ammeter to the ignition switch (probably at the ignition switch itself but that is not important).

[gofer]

Hi L.A.B.,
The Zener lead is on its own. The large female spade connector goes to the Zener at the one end, back to a double crimped white spade connection which I assume fits to the rectifier. From the dbl. crimped rectifier connection the remaining lead goes to the ignition. That's the logical solution.
Correct assumption the Ig.switch is just on/off.
Correct assumption also for the brown/blue wire, doubled crimped at the ammeter, one lead back to the horn and the other to the neg. side of the battery.
Affirmative with the brown/white from the ammeter to the Ig.switch.
My main cause for confusion is the wiring diagram showing a white wire from the Zener which ends up as a double crimped brown/white wire at the rectifier

Have attatched a copy of the wiring diagram indicating my dilema in not understanding the logic of the drawing. It is this that is throwing me out.
The only thing I can assume is that it is a printing error, (which re-occurs on several of the wiring diagrams). The problem is no-one can confirm it.
I've already asked in both Canada, the UK and the US, with diffuse answers.
If as I think it is a printing error, then it's white all the way from the zener to the rectifier and on to the Ig.switch.
Appreciate your assistance , but really hoped a 1966 T120 rider could look under the seat to confirm the colours.

Regards
Gordon

[L.A.B.]

I just wrote up and posted a reply to your message and it has disappeared (that's happened before).

I think I may have discovered why you appear to have white Zener circuit wiring.

I think the harness you have could be the nacelle type?

Look at the DU24875 drawing for the nacelle model, you will see that the Zener circuit wiring is white!

In which case it might be better to use that drawing to wire up!

[gofer]

I already checked it out and although quite a few similarities, the Ignition switch is a different type.
Have now purchased a powerpack, which will get rid of both the zener and rectifier.

Gordon

[L.A.B.]

I already checked it out and although quite a few similarities, the Ignition switch is a different type.

The nacelle switch does appear to be different although it only seems to switch one circuit (connecting white with brown/white)-so connecting up to the switch you have shouldn't be a problem.

Have now purchased a powerpack, which will get rid of both the zener and rectifier.

Probably a good idea if the Zener and rectifier are quite ancient.

Gordon