1997 Dodge Dakota

I have a problem with it running hot on hot days and when the air is on it has a new water pump and thermostat so my concern is should I replace the fan clutch or radiator? I have one friend that says he thinks its the radiator because he used a laser thermometer to check it and it had cold spots in the radiator another friend said that if I could take the fan blades and move the clutch that was it so I checked it that way and it did move but I checked my 92 chevy and it done the same thing and it does not run hot so I am stumped I read one article on the net and it said something about removeing the spring and turning it 90 degrees to lock it but it did not say how to remove it or how difficult I dont want to break it so if anyone has any suggestions please help also it is losing water but not in oil or leaks my son drives it so he couldnt tell. So I dont know if it is boiling out or what.