this video shows what happens when your car fan clutch goes bad, a fan clutch is supposed to have some resistence to it so the engine can spin it with the clutch, obviously,...  when a fan clutch goes bad your car will overheat from the engine not being able to spin the fan blades fast enough since the internals of the clutch are not working anymore, your fan should not freespin more than like a 3/4 turn at most and should be heavy to turn,

being repetative, when the engine is turning with a bad fan clutch the engine will be spinning much faster than the fan does at idle, and your fan will just be sort of spinning just because of rotation not because of the clutch functioning

1st test is bad clutch, you can hear it clicking around inside, i think the clutch may have just basically destroyed itself in this one,

2nd test is a good fan clutch, i got it from my buddy with only 70k miles on it as a stock clutch, its branded aisin for my toyota supra, you can hear even me a big guy is having trouble turning it,