the answer you might be looking for if it is a cooling system then it should be on this site http://www.2carpros.com/articles/how-a-clutch-fan-works
BAD CLUTCH
To check the fan clutch on a 2003 Ram 5.9 diesel, first ensure the engine is off and cool. Start the engine and observe the fan operation; it should spin freely at low speeds and engage more as the engine warms up. You can also manually spin the fan; it should have some resistance but not be overly stiff. If the fan does not engage properly or spins too freely at higher temperatures, the fan clutch may need replacement.
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Yes, the clutch fan should run freely when the engine is stopped. This is because the fan is designed to engage only when the engine is running and the temperature rises, allowing it to provide additional cooling as needed. When the engine is off, the fan's clutch should disengage, allowing the fan blades to spin freely without resistance. If the fan is difficult to turn by hand when the engine is off, it may indicate a malfunction in the fan clutch.
The clutch pedal.
Generally if it is a thread on fan clutch, yes.Generally if it is a thread on fan clutch, yes.
The clutch fan will not cause this issue. The more likely causes are a stuck open thermostat or coolant not flowing properly through the heater core.
As any fan clutch works, it is by the amount of heat. When the engine is cool or below its temp. the clutch will free wheel, in other words it will turn slowly with little force. As the engine heats so will the water temp. then the clutch will pick up the heat and start to engage. Which will start to turn the fan faster to cool. If in the event the clutch stays on in full force all the time, then it has to be replaced.
Radiator in need of cleaning or bad/stuck thermostat maybe. Check the fan clutch to make sure it is operative. The fan clutch doesn't engage until a certain temperature is reached; otherwise it is free-wheeling. It needs to engage in order to cool the radiator.
you have to have fan clutch wrenches
Remove the fan itself then remove the clutch from the fan
The oil can cause the fan clutch to slip against the fan clutch plate. The slipping will wear out the fan clutch plate.