Just had to cancel todays MOT as I have no light at all....Front rear, side lights, dip and also the instrument panel doesn't illuminate! Main beam flash does work though?
Yesterday I was checking it over ready for MOT, everything worked, switched on rear fogs and they worked ok.
Went in the house, had a coffee, tried them all again and now bugger all.
Ive rewired my headlights using a harness and added DRL's again with a ready made harness and all was working.
Ive checked all the wires to the light stalk on the steering column and can't find a live. Checked all the fuses and they are ok (at least the ones I can find)
Can anyone tell me where the live comes from that goes to the stalk?
What confuses me is why the instrument panel has failed as well?
I have some diagrams and can read them to a point but have failed to find how the live is fed?

Oh yeah, its an 87 LR90 with a TD5 bulkhead and I think a TD5 fusebox by the gearstick......this doesn't help!!

If it has glass fuse holders then check voltage to ground across both sides of fuse
Has it got dimdip unit

Tis the season for electrical gremlins - cold and damp.
Be methodical - look for voltage at the fuses, both sides, then at the switch. Most lighting failures are caused by bad earths IME. Run a good earth direct from the battery to the light to check.

The fuses are blade type ones.
I don't know where the Dim/Dip relay is i'm afraid, theres 2 yellow ones by the fuses and I think some more behind the fuses.
Is there likely to be anything under the bonnet, i.e. a dim/dip relay?
I assume a Dim/Dip relay is just a change over type relay? As you can see i'm still fairly new to LR electrics but learning fast. I have a basic electrical knowledge and also common sense, well, a bit of common sense

It sounds a bit like you've answered your own question, in that there's no live feed to the switch, which would explain the lack of lights outside and on the dash. I'd be tempted to put 12v in to the usual live feed terminal on the switch and see if it makes a difference. The flash via the indicator stalk has a different live feed so it's working!

I had almost exactly the faults you describe on my 300 tdi except the no lights only on the drivers side, checked the fuses and thought it wasn't that, but double checked later and it was a 10A fuse right under one with a yellow plastic cover obscuring the melted wire from view.

Cracked the headlight issue, there is a fuse block near the heater box on the bulkhead. Had a hard job finding it as it wasn't fixed!!! There is 3 fuses in there, 1 x 30A that had blown and was the source of the light failure! and 2 x 60A, one of which has blown but i can't find anything not working? Anyone know what each fuse is for? Ive looked on the wiring diagrams I have and can't find anything that shows a 60A fuse?