I googled Discovery seat wiring & found this link: Free Download Wiring Diagram: 2002 Land Rover Defender Electrical Circuit Diagrams.pdf OnlineFreeEbooks the most imitated free ebooks site
I haven't looked at it, & it says it's for a Defender but I presume they'd be at least similar?
And these links too:
http://www.landroverresource.com/ from this thread:
http://landroverforums.com/forum/dis...systems-18287/
Good luck! And be very, very careful. 12V systems are plenty powerful enough to electrocute you, and DC is far more likely to do so than AC.
For the record, I have a limited electrical licence in the state of QLD. I'm not a fully licensed electrician & anyone considering using the information I've provided should consider getting the services of a properly licensed electrician.

