Thank's for that tip on the coolant temp sensor will find out tomorrow when its cold as it was still warm tonight,
What i did notice was when the outer sleeve was pulled back to reveal the two wires, they were twisted and the outer plastic round the wires was cracked and the wires were stuck together so i think this was the prob let's hope so.
I had already changed the sensor so ill just leave it thank's Steve it looks like you were on the right track with the sensor