Sorry but I can't find wiring diagrams in the RAVE, only descriptions and connector details. Can anyone help, it's for a 2002 ?

Here you go

For future ref (and they don't make it easy), you have the workshop manual, the connectors manual and the wiring diagrams manual -> cdlm032n.pdf

[EDiT]

You should be able to actually read this one, the quick upload for the forum resizes images

Click image to enlarge

Hi, thanks for that, so in future is there somewhere I am not seeing on the WIKi that has the wiring diagrams ?

Yes, unless you grab the whole RAVE iso of the net I can't see the circuit diagrams linked to in the wiki.

Here is a link to the wiring diagrams pdf http://ul.to/7myo8nh1

Here is a link to the RAVE download page on here: http://www.fullfatrr.com/forum/topic17363.html?highlight=rave .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Had a wee look at the diagrams & checked all the wiring. You see, ever since I bought the car over 2 years ago, the RH rear heated seat has not worked. The led,s on the switch momentarily light then go out. Swapping the switches made no difference. Anyway today I thought I would have a go & find the fault. After ruling out a few things, using the flash test from Rave gives me three flashes which on the front seats means faulty elements. This is probably correct as using a meter, there is no circuit from any of the three wires on the seat plug. One is earth, another is the other end of the element and the third, a sensor signals back to the switch for more or less power. So at least two of them should have a circuit.

I am unsure if there are more connections within the seat or if it's easily possibly to change the element within. Has anyone done this job previously or opened up one of the rear seats. It's probably a job not worth doing as there is only the occasional brat in the back anyhow but I do like everything to work if it's not too much of a challenge.

On the pre-facelift L322 (<2005) the heating elements are stitched into the seat cover, to replace them you need a whole new seat cover.
As you've discovered the light extinguishing after a few seconds indicates an open circuit, as all the elements are in series it only takes one element to fail to render the heating inoperative.
I'm not sure how many elements there are on the rear seats (the front seat has six) but you might be able to disconnect the one (or more) faulty element and jump the connection completing the circuit for the remaining elements to work.
Start by testing each element, each one should be around 0.7-1.0 Ohm, anything outside this indicates a potential fault.
The only element that needs to work correctly is the seat base as the temperature control circuit looks at the heat produced by this element and regulates the heating (it does on the front seats, I assume the rears are the same), if this element doesn't work and is jumped then it could lead to overheating...the elements do burn the seat if damaged so be careful!