Thanks CE for your response. The cooling fan clutch is working properly. Flushing the system. First, I drained all the coolant out of the radiator. Second, I removed the radiator cap and the drain plug at the bottom. Using a hose and with the engine idling I let the clear water run thru the system. Third, I replaced the radiator cap and drain plug. With the engine running i let the clear water pump thru the system. I then turned the radiator cap to the first notch to release the pressure. Fourth, using the hose i flushed out the coolant resevoir, until i was getting nothing but clear water. Fifth, I filled the resevoir with 50/50 coolant to the "Cold Fill Mark". Then I filled the radiator with 50/50 coolant.
It did not resolve the problem. As soon as I started the engine, the gauge went to straight to HOT and remained there. I drove the truck about 10 miles at speed from 40-70 mph. I shut the engined off and waited til the engine cooled and drove back another 10 miles...Same problem...the heat guage stayed in the HOT zone.
Verifying the water pump is actually moving water. I removed the hose coming from the block and clean water came thru when I flushed the second time. The truck overheats as soon as I turn the ignition on and start the engine. At rest and when the engine has cooled the gauge does move up barely into the normal range on the Hot side of the guage. Now, SOMETIME, (and rarely) the needle will move up into the normal range on the high end of the HOT side.
It has never boiled over, UNLESS I turn the a/c on.
I think I have answered your questions and hope they will give you a better insight to my problem.
Again, thanks....