Air Conditioning (coolant?) Problem '01 Taurus

I am having the following problem:

A/C clutch de-energizes occasionaly during city driving or driving at

75 mph with my back to the wind. It generally will go out for about 10 minutes and then can run for an hour.

With the A/C on my temperature is usually right in the middle of the "normal" band. I did notice that when driving at 75 with wind pushing me that the needle slowly creeps up to the higher end of the normal band (about 90% of the band) at which time the A/C shuts off. When the needle drops back down to about 2/3 of the normal band I can feel the A/C clutch engage and cooling resumes.

I suspect I am having a cooling problem and not an A/C problem. Car has 140,000+ miles on it. Otherwise everything runs great.

I can idle it in the driveway and see that the fans run on low. I then pull the low speed relay and the fans run on high. Coolant level is OK.

I suspect thermostat is OK as it normally maintains in the middle of the band.

Any other thoughts on what I could check? Would a radiator flush possibly help?

I expect you are right... your A/C system is actually operating as it should.

Only three questions...

have you checked rad/condenser for debris?

Are your fans running on high prior to A/C shutdown?
Is your actual coolant level in the pressurized part of system, full with no airspace?

If the answer to above is yes, then check coolant for clarity.. if at all muddy, do a flush. If oily, other problems exist.

If you have driven it that 140,000 and dont recall servicing the coolant, then do the flush/refill anyway. Note that MORE ANTIFREEZE perWater ratio isNOT better! mix only to the environment you are in.

If okay then go to Pep Boys "or other fine store" and buy a bottle of Red Line Water Wetter. It will fix your problem right up.

"Gimp Studley"