A fan clutch is the assembly that your engine cooling fan rides on and that tells the fan when to turn on and off. A central core, which locks and unlocks based on the temperature, allows the fan to spin with the engine crankshaft or freewheel on its own. A bad fan clutch can leave you without an operational fan, which in turn prevents the proper amount of air to cross through your radiator core. Without enough air over the radiator core, your engine can overheat in a matter of minutes. If you determine your fan clutch is faulty, replace it immediately.
Things You'll Need
- Safety glasses
- Stiff piece of cardboard
Put your safety glasses on and climb under the vehicle with your flashlight. Look up at the underside of the fan clutch and inspect for any leaks from the clutch itself. Climb back out when you are done.
Raise the hood, with the engine off and cold. Reach in and spin the fan blade by hand. If it continues to spin freely for more than five turns with no signs of drag, you have a bad fan clutch.
Start the engine and look down at the fan. The fan should be still or barely revolving until the engine warms up. When the fan begins to turn at engine speed, move to Step 4.
Push the piece of cardboard down into the spinning fan, being careful to never get your hand or any part of your body or clothing anywhere near the fan blades. It is best to do this from the front of the vehicle, instead of the side, so that any pieces of cardboard knocked loose will not fly up at you.
Watch the fan to see how it reacts to the interference from the cardboard. If the fan begins to slow down, or comes to a halt altogether, your fan clutch is bad and should be replaced. If not, your fan clutch is working properly as long as you have seen the fan cycle on and off during this inspection.
Tips & Warnings
- If your fan never stops turning, you should replace the fan clutch.
- Photo Credit Jupiterimages/Comstock/Getty Images
How to Replace the Fan in a Chevy Impala
The Chevy Impala was manufactured from 1958 to 1985, then brought back into production in 2000. The type of fan in the...
How to Check a Radiator Fan
Your car's radiator holds coolant fluid for the motor to ensure that the motor doesn't overheat. If the fan on your radiator...
How to Test a Fan Clutch
You might not think it, but your car's belt-driven cooling fan can take a lot of power to turn. When James Watt...
How to Replace a Trailblazer Fan Clutch
The fan clutch is responsible for pushing radiator fluid through the water pump, which keeps the engine cool. Specialty tools are needed...
How to Remove a Chevy Fan Clutch
The fan clutch on your Chevy helps the cooling fan blow air through the radiator and over the engine, thus helping the...
How to Troubleshoot the Fan Clutch in a Ford Explorer
The Ford Explorer fan clutch is responsible for the performance of the engine cooling fan. The engine needs to operate at a...
How to Test My Thermal Fan Clutch
A fan clutch that is not working can cause many different problems. The engine can overheat or even run below the proper...
How to Install a Thermostat for a Chevy S-10
The thermostat in your Chevrolet S-10 is simple to access. The easiest way to locate the thermostat is by tracing the top...
How to Troubleshoot a 2004 Dodge Cummins Fan Clutch
Everyone enjoys the cool air from the air-conditioning unit on a warm summer day. Using your air conditioner, however, causes wear and...
How to Check Clutch Problems
Clutch problems can have various causes, and you can check most of them yourself in order to diagnose the issue. If the...
How to Replace the Water Pump in a 97 Blazer
A water pump on a 1997 Chevrolet Blazer passes coolant through the radiator to the engine. The coolant temperature is lowered in...
How to Fix a Clutch Fan
Commonly misspoken as "clutch fan," a faulty fan clutch is an often overlooked cause of engine overheating, as the fan clutch helps...
What Are the Signs That Your Fan Clutch Is Going Bad?
Some engine fans are controlled by a belt attached to the car's engine, meaning the faster the engine goes the more the...
2003 TrailBlazer Fan Clutch Problems
The fan clutch in your 2003 Chevy TrailBlazer is mounted between the fan and the fan belt pulley on the water pump....