I'm not too familiar with the details of the later (or alternative)wartime electrical circuits and am seeking some clarification....

What was a DU42 fitted to that had the 'normal' 4 position WD switch but a blanked out ammeter?...In the ammeters normal location is an electrical component which may be a resistor or similar...

This is not the system with the 'test' switch in place of the ammeter....

Any comments?...Ian

email (option): ian@wright52.plus.com

Hi Ian,
What you are describing sounds like what is fitted to the James ML.
The "test" type switch is normally fitted to a bracket and located under the saddle. A small push button change over switch (to switch between pilot and main bulb) is located in the ammeter position (G3L) or in the main switch position on other models.
Cheers, Mick.

email (option): mick@motorbikemike.org.uk

The ML has a unique switch with Off.T.H.L. and no Lucas logo. To my knowledge, no other bike is fitted with this switch. RON

email (option): ronpier@talk21.com

Mick is correct........whilst the DU42 head light assembly complete with blackout mask is a standard "universal" WD fitting, including the switch panel, the fittings are unique to the WD James ML only.........

The switch panel has a loose blanking disc fitted over where the ammeter goes......this has a central pin which supports (underneath) a copper-wound circular bakelite resistor..........

As for the switch itself, this is also unique to the James ML.......whilst it has 4 positions, it is marked "OFF, T, H, L" rather than the common "OFF, T, L, H"..........it is the internal central rotor that is unique to this model as well as the top of the switch, the former having different raised portions to operate the contacts.........although (probably) made by Lucas, the switch does not carry the "Lucas" name on the top face..............

Obviously, the ML switches are rather rare today as they made slightly less than 6000 WD bikes plus spares.......and few original bikes still carry them, most bearing the more common Lucas WD 4-position switch............my own ML has the correct type fitted however and I've found a couple mis-described on Ebay over the last couple of years as "WM20" items.........

Hi Mick..The standard WD light switch is in the normal position...There is no exterior switch where the ammeter is normally fitted...In that location is a blanking plate and the electrical component is located under that plate (and is around the size of the ammeter)

All that is visible from the exterior is the screw (in the centre of the blanking plate) which, I think, retains the electrical component beneath it....

I'll have to take some photos and post them to show what I mean...Unless someone recognises the set up...

It is a complete NOS DU42 with this arrangement as original fitment...Ian

email (option): ian@wright52.plus.com

Thanks Ron...The picture answers the question...That's what it is...

So I have a complete NOS James ML headlamp it seems.....

I suppose if I replace the switch panel complete I have a standard DU42?....Ian

email (option): ian@wright52.plus.com

Sounds like the James ML arrangement that Ron pictured Ian !

Yes, without the switch panel you have a standard DU42.........

As for the ML switch panel, as stated, quite sought after !

I'm guessing you've just bought the NOS one off ebay Ian

email (option): horror@blueyonder.co.uk

Here is that direct lighting resistor Ian! Does you headlamp have the odd ML switch? The switch panel will make a nice item for an ML owner.Ron

email (option): ronpier@talk21.com

Horror is correct...I bought the NOS headlamp off ebay...

It is complete with the correct ML switch etc. etc...It even has the electrical inspection stencil on it...

I paid a fair bit of money for it, not realising the switch is slightly different...hey ho...

It was that I was after primarily...I now have to decide whether to sell it on as a complete unit or whether to sell the switch plate assembly and build another DU42 with what's left and some other NOS and good parts I have... ...Ian

email (option): ian@wright52.plus.com

Well it would be a shame to break it up and lose the stencilling. I never re-spayed my NOS ML headlamp so as to preserve the stencil, which so far is the only one I've ever seen. But it's almost the same colour as the OD that I sprayed the bike with. Ron

email (option): ronpier@talk21.com

Hi Ian
If you were interested in selling the ML switch assembly i would be very interested!!! I have a couple of standard DU42 switch panels and a standard switch also that although incorrect i was going to use on my ML restoration, but would love the correct original item if you were interested in a trade somehow?!!!!
Regards
Daren