How to Check a Radiator Fan

by Erin Stewart

Your car's radiator holds coolant fluid for the motor to ensure that the motor doesn't overheat. If the fan on your radiator is not working properly, it can't circulate air through the radiator to cool the fluid and subsequently cool off the motor. If you have had problems with your engine overheating, check your radiator fan and water pump. If you ignore the problem and let your engine overheat, you run the risk of ruining your engine completely.

Determine whether your radiator fan is manual or electric. A manual radiator fan is bolted to the water pump and runs off of the same belt as the water pump. An electric radiator has wires that connect it to the car's electrical system.

To check an electric radiator fan, start the car and let it get up to the temperature where the fan normally kicks on.

Use the volt meter to test if there is power to the wires. Connect one end of the volt meter to a ground and the other end to the electrical connection on the fan. The volt meter will then give you a voltage reading.

Normal voltage for a radiator fan is around 12 volts. If the volt meter reads 12 volts, the problem is not the power and the fan needs to be replaced.

If the volt meter reads that there is no power, check your fuses.

For a manual radiator fan, conduct a visual inspection first. Make sure that the four bolts holding the radiator fan are tight. Make sure the belt is in good condition and has tension.

Some manual radiator fans have a fan clutch. The fan clutch has a spring inside of it to help the fan spin faster. If your radiator fan has a fan clutch, check the radiator fan while the motor is running. The radiator fan should be running at more RPMs than the motor. If it is not, the fan clutch is bad and needs to be replaced.

Some radiator fans are solid mounted, with no fan clutch. If your radiator fan is solid mounted and the fan is not working, your belt is bad and needs to be replaced.

Tip

  • check It is uncommon for radiator fans to go bad. In most cases, the water pump is bad and isn't pumping fresh fluids.

Warning

  • close To check a radiator fan, you will be dealing with a part of the motor that has a lot of moving parts. Use extreme caution to avoid getting injured.

Items you will need

About the Author

Erin Stewart is a professional editor and copywriter who has served as a newspaper reporter, designer, and news editor, and currently works as part of a dynamic marketing communications team. Erin has a Bachelor of Arts degree in English with an editing minor from Brigham Young University in Provo, Utah.