Found the fault!!! Its the red wire that comes off the main loom behind the dash and goes to a connector ( maybe the one as mentioned by treesurveyor) and then on to the ignition.
It has been rubbing against the support for the dash ( the right upright, the edge of it) and then obviously shorted when the plastic was breeched and sort of melted itself to the metal.
Pulled it away and wrapped it with insulation tape and repositioned the wiring ( its like a birds next behind the dash) with a cable tie and all seems OK although there is lots to put back before I start the car.
But the ignition is now coming on and lighting up the dash so I am pleased.
Thanks for all your help and especially to Richardv6 for his efforts on my behalf.
