Thanks for your reply
However" The tech was saying if everything is right the fan will rarely go on -- the engine driven fan on this model is very large and powerfull and does a good job of cooling the system. He was saying that the high water temp cut in is very rare and could indicate something else up -- unless you were in very hot weather

If you bypass the pressure switch the fan will run all the time - even with the ac off! So this simple change will not solve the problem."
On my car - when I travel when it is above 90F outside on the highway - my engine temp rides about 95C with the a/c off - which is OK. When I put the a/c on - the engine temp climbs to 110C after about 10 minutes and the aux fan does not come on high - from what I have read on the subject - the fan should kick in at about 105C. It doesn't. When I bypass the pressure switch - the fan does NOT come on. If I apply 12v to the fan - it works at high speed AOK. That is the problem. That is why I feel there is a relay problem - but where?? If you have any idea why - I would appreciate it. If I find it this week end - I will tell you Monday.
Thanks
Morris