a fan clutch is to spin the blade by hand with the engine stone cold and not running (of course), the fan blade should spin freely. If it doesn't then the clutch is bad...to be sure run the car around until the motor is completely warmed up and then turn the car off and try to spin the fan again, there should be considerable resistance compared to the cold start test...if seems the same then it's same problem...clutch is bad..I gotta tell you though, I have never ever seen a fan clutch go bad to the point of causing cooling issues.....