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[DogDave]

So completed the new bulkhead which required pulling the wiring loom to bits and through the old one, and back through the new one. Thought I had been meticulous in labelling everything and putting back where it should be.

I have electrics to start and run, side lights, wipers, dash lights and screen wash. Don’t have anything to headlights, indicators, hazards, horn or fog lights.

Working through it trying to figure out - it’s not the ignition switch  as the wires coming off that are live when should be, all fuses are tested and OK.

Anyone see anything similar at all? Tracing is difficult as when it’s gone from Land Rover to Marshalls to St. John’s and after various alterations have happened so wires are rarely the same colour at both ends now.

[jonhutchings]

you mention is ex military, but it sounds like it it's not a GS, maybe an ambulance? A few details might help as the wiring differs on some of the military versions. Did it have the 6 way convoy light switch ?

[DogDave]

Sorry, yes it’s a 1981 registered Marshalls ambulance - crash rescue version for RAF it’s 12 volt.

It does still have the six way switch - so sidelights are working on that switch - but headlights are not

Puzzlingly the dashboard main beam warning light is working even though there is nothing coming through headlights on either dipped or main.

[Wittsend]

The MoD 6-way switch is a nightmare to deal with 

We must have a wiring diagram of it somewhere and probably one for the Marshall ambulance and then it's a case of studying the diagrams against what you have.

I doubt us armchair electricians can help that much....


 

[DogDave]

Ok thanks - I’d kind of discounted that as the sidelights were working but if it’s a known source of gremlins I’ll have a study of the diagrams on the website tonight and see if any clues to be had

[Wittsend]

The problem I have on the LWT is that the 6-way switch is covered in a huge, rather inflexible water proof sheath which makes looking inside it almost impossible as to which wires go on which terminals 

If you are lucky you may have better access.


 

[DogDave]

The problem I have on the LWT is that the 6-way switch is covered in a huge, rather inflexible water proof sheath which makes looking inside it almost impossible as to which wires go on which terminals 

If you are lucky you may have better access.


 

Nope exactly the same problem here. But then goes into a 6 way connector that can only be done one way so i had assumed had got back as it should be - but then easily something come loose in undoing and putting back.

I have horn back now as one of the wires going to the fuse box was wrong- oh and rear fogs have come back but not front.

[Wittsend]

Maybe some switch/contact cleaner in the connector block

 
Don't use WD-40 or the like - use proper contact cleaner formulated for this job.
Or, at a pinch use some aerosol brake/carb cleaner.

 

[DogDave]

Only have wd40 so a badge but tried that, and there are similar blocks to the indicator stalk as well so done them - still no change. Puzzle that no indicators either although it could of course be 2 different problems at the same time.

Think some time on a pc looking a diagrams will be the answer

[diffwhine]

This should be the wiring for a 6 way switch.
Have you got a military wiring diagram?

[autorover1]

Is there an infra red switch as the headlamps go through that .

[nathanglasgow]

Fairly sure IR was a series 3 thing.

[DogDave]

I don't think it has a infra red switch - if it has I haven't found it yet (which is fairly plausible but i'd have thought I would if it was there.

I think next step is taking the connector block off and jumping the connections to see if the switch is faulty somehow using that diagram - that should tell me if the fault is the switch or elsewhere i guess.

[DogDave]

Ok pretty sure it’s not the switch. I can jumper the wires and amazingly the colours are right this time. Live is live, live to sidelights works, taillights work

Live to headlights - nothing happens - live to indicators nothing.

So something else is not as should be somewhere although why there should be anything between headlight and switch that would point to the combined indicator / dip main stalk I will attack that next

[diffwhine]

I'd certainly do checks round the dim dip switch. They can fail and potentially leave you without anything. The operation is the same as a civilian vehicle, so the wiring checks in the workshop manual should help. Easy one to check