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.
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.
Do have a close look at the rub point before you put everything back together, particularly if the cross sectional area of the cable has been diminished. Each time it shorted out, some of the copper would have been vapourised so it is possible that some of the strands could be broken and then might over heat in the future.
