I'd not been using the Red Special for a few months, and when I checked the lights in contemplation of the Controle Technique (=MOT), I found I had some but not others.

The headlights, dipped and main, were fine. The indicators too. But none of the sidelights were working, front or rear. The horn worked, and the wipers. I haven't currently got a foglight fitted but the tell-tale for it on the dash came on too.

I found the Haynes wiring diagram utterly unhelpful, but I checked the fuses, all four of them, with a multi-meter, and none were blown. At the end of that the lights still weren't working.

Then the next day I started it up and everything was working. Assuming it wasn't simply divine intervention, it presumably was one of those fuses making a bad contact in the holder, and which had settled back in the right place after I'd fiddled with them.

But is there a single fuse for just those lights? Or can it have been a bad connection elsewhere (eg the switch?).

It's obviously not urgent but I'd appreciate any comments.

Oh, and a happy new year to everyone!

Bad earths? I added an earth wire to my headlamp bar that takes the earth from all the lights via a bus bar that's connected to the battery. The difference is astonishing.

I also ripped out all the old wiring and replaced the primary feed to the light switch with new 10a wire running through it's own dedicated fuse.

Dennis & Sam,
it's most unlikely that all four side & tail lights would develop 'poor earths' at the same time, which makes dodgy contact on the single fuse which serves them and the speedometer bulb the prime suspect.
I've found that it's quite common for this fault to develop on cars which are left standing for long periods.
With the original style of fusebox, the individual holders can be removed, cleaned up with a chainsaw file and refitted after being coated with petroleum jelly (aka Vaseline)...

It's possible that it's a poor contact onto the light switch drum but as Ken says, the fuse is much more likely:

It's the 10amp fuse with the red cable-sleeves.

Thanks very much. I wondered about the switch. I'll clean up all the fuse holders (and the fuses), but particularly that one with the red sleeves, before it goes out again.

Indeed I lost my sidelights and discovered that in y hast to stick the car o the road I'd neglected to remove the spiders, leaves and other organics from the fuse box

As an aside I usually wire my speedo light to come on with the ignition.

Wasn't that the way they were made (late models anyway)? Mine certainly does, and I haven't rewired it.

Ah that's interesting. I thought not. My 88 comes on with the side lights but the 87 is with the ignition. 85 is with sidelights

My 88 reg, 87 manf.d ...comes on with the lights....[car is totally "mint" btw, I've owned it from new...and know all its history].
T.

Why would you want your speedo light to come on with the ignition - I can hardly see mine even when its dark. I have a 50 - 0 - 50 ammeter which indicates that the ignition circuit is on when you turn the key.