I should tell you before i start this that i am an electrical engineer. I have just bought a 15 year old defender 90 200tdi, the heated rear window doesn't work and the haynes manual i used is not very clear as far as the electrical schematic goes. before i dissasemble (no.5) my dash board to gain access to the relay in question has anybody got any clever suggestions ? i have tested at the switch and i do not have 12v on either leg. i have checked the fuses and all are ok. PLEASE HELP !! or else i will just have to free up a day which aint easy . !!

 

I'll assume you checked for voltage on the rear window??? and that the other lead is indeed grounded ???

 

Mine's doing the same ('93 L plate 200 Tdi deepender) - haven't really looked into why yet but did notice a 'spare' (as in not currently plugged into anything) connector block hanging under the rear crossmember while I was jet washing the underside earlier.

Have a quick look under the back of yours, if you've got the same thing there we might have found a 'quick fix'.

Is the relay for it not under the fuse box cover in the cab then?

 

i wished it were, according to the haynes bible it is behind the dash and i have removed it enough to see it there, however to actually lay my hands on it i will have to disconnect the world and its mother. not a problem now because its spring/summer but by autumni may well have a bigger issue. ( no im not homeless ) . I am toying with the idea of just rewiring it from scratch. it may be an easier option than trying to get to the bottom of my problem.
Thankfully i love a challenge. ;-)