Should a Fan Clutch Spin Freely When Cold?

Engine cold and off. If you can spin the fan freely, it is bad. If good there will be considerable resistance.

How stiff should a fan clutch be?

There should be a nice, consistent, deliberate rotating force such that when you let the fan go, it should start spinning back up at a rather rapid rate of rotation. If right after you release the fan to spin, and the fan spins ever so slowly, then your fan clutch isn't working right.

What temperature should a fan clutch engage?

At what temperatures do fan clutches engage? Answer: Most fan clutches engage at about 170°F air temperature (about 180-190°F engine temperature). They reduce the temperature about 20°F before disengaging.