Chaps,
Well Tim kindly printed off a large copy of the wiring diagram, and even spent some time with his multi meter trying to identify the problem, all to no avail.
I took all the lamps out today and checked the in-line fuses which were fine, so I am now at a dead end, so have contacted Martin Cliffe and will drop it up to Omicron in the next couple of weeks and let his chaps loose on it.
Bear with me on this, as I will let you all know what the problem/solution was just in case any of you have the same problem in the future.
I still hate electrics !
Thanks Tim.
Bob