Finally tracked the broken wire but had to remove the ABS unit and pump so that I could get to the wiring loom. Found it was a white wire with red stripe and silver dots. Loads of them on the wiring diagram so that became a bit more difficult to decipher. Took a chance and soldered a new wire in and then connected it to what I thought was the correct wire in the footwell. Managed to burn my hand and arm with the soldering iron several times before I got the job done. Put back the ABS unit and then came the moment of truth. Turned the key and the fault was still there!! Blast (or words to that effect) and back to the drawing board.
Much head scratching ensued and then in what can only be described as a flash of inspiration I went searching for another white and red wire and found one! Resoldered the wire to the new one and bingo! she fired up as normal. I've done a couple of runs in her now and she's as good as new but I have to admit that at one stage I thought she was finished for good and I'd be selling parts of her on Fleabay.
Tc