Hi, to take the temp readings I used a industrial digital meter with the prob clamped to the thermastat housing, the dash temp gauge works and the heater and controls work o/k, it's just that when the car is traveling it all runs cold and when stationary ticking over everything works as it should.
It's doing my head in not knowing why it's doing it but the car runs like a dream otherwise.
The radiator is the correct one and it made no differance to the problem after I changed it.
Baffling an't it!
Dave.