Hi Damian
Done quite a bit more investigation on this now, and the diff lock light has started working after wiggling the wires sticking out of hte transfer case.
The fuel gauge, on the other hand, is stuck on zero... I think they are meant to be connected into the bottom of a connector at the bottom of the front bulkhead, but I can't convince them to stay in at the moment. I bit of friendly persuation and some gaffer tape will no doubt do the trick when I get round to sorting it out next weekend...
The wires are black and green...
Thanks
Ben