[Karl]

Thanks Guys I think I nailed it this afternoon -I discovered a loose connection on one of the wires into the ammeter (In fact into The Chex Oil Pressure /Ammeter gauge - originally my car had the one wire ammeter) I fiddled with it and then there was no power at all to the car a further fiddle and power back again. I have now tightened things up and have power. May well have been the problem as things heated up the loose connection became intermittently no connection -Time will tell -Karl