Instrument panel lights not working

So my 1994 ex military defender has defeloped a fault where the speedo/fuel/oil temp lights as well as the rear lights have stopped working

Headlights, sidelights, all indicators, rear fogs all work fine. I found a blown 5A fuse in the fuse box, which I replaced with the closest I had to hand (4A) which blew immediately upon turning the lights on.

Any idea if the problems are related, and if so any ideas on how to fault find?

I thought about checking the earth for the lights but the haynes manual wiring diagram doesn't actually tell you where all the points are located on the vehicle.

Take out the tail light bulbs.
Replace the fuse.
Turn on the lights ... what happens ?

Replace the tail lights one at a time ...

miktdish said:

Take out the tail light bulbs.
Replace the fuse.
Turn on the lights ... what happens ?

Replace the tail lights one at a time ...

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Taken both tail lights out, replaced fuse. As soon as I switch the lights on the fuse blows with no bulbs in the rear.

In the rear corners there are two tin, triangular shaped boxes, inside the offside one (right when standing at the back door) are the connections/supply for the rear lamps etc, have a look in there
Have a look in both sides, there maybe a short ...

miktdish said:

In the rear corners there are two tin, triangular shaped boxes, inside the offside one (right when standing at the back door) are the connections/supply for the rear lamps etc, have a look in there
Have a look in both sides, there maybe a short ...

Click to expand...

Thank you, that will be next on my list. I did check the relay for the rear lights which is showing the correct resistance, and also checked all the bulbs/ earth points for the instrument lights, all seemed good, no loose wires or blown bulbs.

djawesome123 said:

Thank you, that will be next on my list. I did check the relay for the rear lights which is showing the correct resistance, and also checked all the bulbs/ earth points for the instrument lights, all seemed good, no loose wires or blown bulbs.

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All wiring seems intact for the rear lights, have also pulled the gaitor off the military light switch, all looks good under there.

djawesome123 said:

All wiring seems intact for the rear lights, have also pulled the gaitor off the military light switch, all looks good under there.

Click to expand...

Unplug the loom that goes to the rear(in the engine bay) replace fuses & try again. You may have a short inside the chassis

Hicap phill said:

Unplug the loom that goes to the rear(in the engine bay) replace fuses & try again. You may have a short inside the chassis

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So I unplugged all 4 connectors in the engine bay that ran into the chassis then plugged them back in one at a time and tested the switch. The only one that blew the fuse was this one:

djawesome123 said:

So I unplugged all 4 connectors in the engine bay that ran into the chassis then plugged them back in one at a time and tested the switch. The only one that blew the fuse was this one:

Click to expand...

The wires on the plug are Green with red, Red with orange, Green with white, a smaller Red with orange/yellow, Green with purple and Red with Yellow.

This seems to correspond with the Haynes manual diagram for Left and right indicators, left and right tail plus fogs and brakes.

Out of these 4 the brake lights work, the fog lights work and the indicators work, it is just the tail lights that keep blowing the fuse. Does anyone know where the earth point is for the tail lights as I can't see anything obvious

Tail lights should be separately fused(these are sided fused front & rear)
So could your problem be the towing electrics then?

If it's military have you checked the convoy lamp if still fitted and the trailer socket

So just to clear up the mystery I bit the bullet and took it to my garage, 2 hours labour later and it turned out it was the live metal strip in the numberplate lamp which had come loose and touched metal it shouldn't have been touching, causing a short Just wish i had had mysterys magic diagram before I took it in