Hia all, could I pick some brains please, I have a 1990 defender and I recently brought, soughted out a few jobs but the one I cannot do is get the rear demister working, electrics ain't my thing , I have 2 wires that go to the switch there is power on one wire but when switched on I get no power at the leads near back door and also the warning light on the dash does not light up, think it could be either the relay, the sensitive voltage thing like a yellow relay behind the dash or the actual switch, any ideas which one I should try first before I end up buying all three, any help appreciated thanks

Have you checked the foil strips on the rear window are in tact before going to all the trouble of chasing an electric fault. Like you say check the relay and ensure you have a good earth at the back.

Just remember there is no more satisfying job than diagnosing an electrical glitch

I have checked the wires just inside the back door where the wires come out behind the lights the is a connection and there is no power getting there so must be up front somewhere, the foil strips on the back window all look intact and in good condition, is it possible I could bypass the relay and voltage thingy just to see where the fault lies