Help, Dash Light failure... but not.

Odd thing is happening with my dash lights, when I turn my lights to 'side-light' all comes on as normal. Side-light, rear lights and dash lights. But when I turn the main lights they all come on as normal, but the rear lights go off.
Now I'm going to pop all the connectors off when I get five and check them for 'fuzzing-up' but is there any particular spot I should check. After all there is a lot of places with cable, and I have no idea where I'm tracking it all.

Another development here, turns out when I put the main lights on the side light goes off. So some how the dash and side lights are connected. When I flicked the lights of and on rapidly after about 5-10 flicks all the lights came on normally. So it looks as though it could be related to the switch, so I'll whip it off this weekend and have a look.

Originally Posted by Grinch

So some how the dash and side lights are connected. When I flicked the lights of and on rapidly after about 5-10 flicks all the lights came on normally.

That would be via the ground (-ve) cable from the dash through to the side lights.

After your first post, I was suspecting a dodgy earth but didn't like to say. You've just convinced me. I reckon it's probably bridging from either the dash or side lights -ve to the headlights -ve. But that's just a stab in the dark (pardon the pun).

EDIT: Take a gander at the In colour wiring diagram on the main site. The dash is top left. From there, you've got a B/W wire running down to the front lights (sidelights, indicators, headlights) and that feeds from your right headlight back down to the rest of the loom. There's also another B/W wire that runs from the dash back to the loom. I reckon this is your problem, or somewhere there anyway.

EDIT2: It's actually the same B/W wire that passes thru the harness to the rear lights too.

Ta, I'll give it a good look over this weekend, looks like pannels off then...