Chasis A/C condenser - blocking air lfow to radiator?

Since I've never heard the clutch fan I am replacing it. Not sure if this is a valid test but when I removed the clutch fan I applied some heat to the thermal coil. It did move but I could still turn the fan by hand. Not sure if more than the coil needs get hot before the clutch would kick in. Either way, everything I have read say's that the sound is unmistakable and I just don't hear anything different hot or cold.