intermittent random selection of rear lights not working

[ambivert]

My rear lights are playing up! Some of them work some of the time, is the best I can describe it:

* indicators (both sides, rear only) stopped working, but have now started working again mysteriously (after I waggled all the wires I could find behind the dash and going into the light clusters... but not immediately after)
* reverse lights don't work at all (but I'm pretty sure they did last year)
* main lights only seem to working on one side (if at all)
* brake lights almost never working (sometimes comes on, on one side)

I have replaced a few bulbs and cleaned up some cruddy contacts in the light clusters which helped a bit, but not totally... I only seem to have noticed these problems since all the cold weather started just before xmas...

I'm now going to have to individually test each bulb, and each pin in the light cluster's connector blocks, with an external 12V supply to rule out faults at that end. Having done that, I'm going to work back all the way back to the control switches and fusebox until I find out whats going on here.

So, my question is: where do all the wires actually run, from the rear clusters?
More specifically...
* Do all the wires run inside the van or along the underside?
* Does the reverse light's wire go to a sensor in the gearbox (or is it somewhere under the gear stick?)
* The brake light's wire must go to a sensor somewhere in the braking system (under the brake pedal maybe?)
* What about the main lights, they must just join into the same wire which feeds the headlights? Where is that junction located?
* Indicators - I guess the wire for those must also join into the same wire which feeds the front indicators? Where is that junction located?

All advice, suggestions welcomed!
cheers
Vince

1.9 manual 4 speed petrol DG devon poptop 1984 RHD

[Syncro G]

My rear lights are playing up! Some of them work some of the time, is the best I can describe it:

* indicators (both sides, rear only) stopped working, but have now started working again mysteriously (after I waggled all the wires I could find behind the dash and going into the light clusters... but not immediately after)
* reverse lights don't work at all (but I'm pretty sure they did last year)
* main lights only seem to working on one side (if at all)
* brake lights almost never working (sometimes comes on, on one side)

I have replaced a few bulbs and cleaned up some cruddy contacts in the light clusters which helped a bit, but not totally... I only seem to have noticed these problems since all the cold weather started just before xmas...

I'm now going to have to individually test each bulb, and each pin in the light cluster's connector blocks, with an external 12V supply to rule out faults at that end. Having done that, I'm going to work back all the way back to the control switches and fusebox until I find out whats going on here.

So, my question is: where do all the wires actually run, from the rear clusters?
More specifically...

* Do all the wires run inside the van or along the underside?
Underneath, they go out behind the front left headlight in one big fat sleave, down along the left hand chassis rail underneath and come out in the forward left side of the engine bay. Here they join into the rear loom, probubly in the black junction box - I'd be most suspisous of eather this area or just behind the fusebox in the cab where this loom starts.

* Does the reverse light's wire go to a sensor in the gearbox (or is it somewhere under the gear stick?)
Gearbox, left hand side of van towards the top I think.

* The brake light's wire must go to a sensor somewhere in the braking system (under the brake pedal maybe?)
Yep, on the master cylinder (there are 2 hydrolic switches (one for each brakeing circuit), eather should trigger both lamps, they work regardless of ignition key), think you can get to them from under the dash pod cover, but if 1 bulb comes on there must be a bad conection/blown bulb at the back of the van stoping the other one as they both work off the same wire going to the back - if only 1 bulb works intermitantly sounds like there is 2 faults to find, one definately in the back, the other probubly in the same place as all the other rear lights.

* What about the main lights, they must just join into the same wire which feeds the headlights? Where is that junction located?
side/tail/numberplate lights share the light switch with the headlights but their operations are totally indipendant as they use completely seperate surplies which is why they work when the key is off whereas the headlamps don't). Somewhere at the front of the van (lightswitch on late vans, fusebox on early ones I think) the sidelights split into 3 seperate fused circuits Left side/tail (58L), Right side/tail (58R) and numberplate lamps (58), the front sidelights then split off these, and then all 3 run as seperate circuits to the back of the van.

* Indicators - I guess the wire for those must also join into the same wire which feeds the front indicators? Where is that junction located?
A bit like the other lights, wire runs from the direction switch to behind the fusebox where each side splits off to the front and rear looms.

As you've got so many different circuits not working its most likely a conector or cable ware in the routeing to the rear (cable ware, though possable will probubly blow a fuse so stop the front lights too, chances are its a dirty/loose conector). Give the earth point in the engine bay a good clean too. Don't forget the rear foglight too (will only work with the ignition and headlamps on) or it'll definately not be working for the MOT.

All advice, suggestions welcomed!
cheers
Vince

1.9 manual 4 speed petrol DG devon poptop 1984 RHD[/quote]

[ambivert]

wow, thanks, saved me loads of time doing all that detective work!