The wire between the main relay and the inertia switch was the dodgy one (think it is white with a green trace).
The plastic had a slight slit in it and there were only two strands left - strange as it had nothing to rub on and was wrapped in conduit sleeving !
Seemed to test ok with a multimeter but could not pass load so stripped back and twisted together and now works
Spent the last few days refitting all the dash, boot floor and wiring plugs etc that we had removed to test.
Now just awaiting an injector loom to arrive along with a replacement relay and base for the glow plug relay.
Im going to seal the ECU casing back up but need to find two screwes for it to replace the missing ones but they are proving hard to find
Massise thanks to everyone that gave advice, came out to look and offered to help - its all been very much appreciated
fixing/ fastener place
