What You Need to Know About Your Car Radiator Fan
A radiator fan blows air through the radiator to cool down the engine’s coolant temperature. It’s essential for a car that idles in traffic or travels long distances.
The cooling fans can be either electric or mechanical. Mechanical ones use a clutch and pulley system.
To check your radiator fan wiring when it’s not working, unplug both wires and test for current with a multimeter.
1. Motor
The radiator fan motor is the part that drives the car cooling fan. It’s the most likely part to break down, and for this reason, it’s usually replaced first. Depending on your vehicle, you might have an electric or mechanical fan motor. The cooling fan is a vital component of your engine’s temperature management system.
The cooling fan blows air across the radiator and removes heat from the coolant, keeping it at a stable temperature. Without a working cooling fan, the engine overheats quickly, especially at low speeds or while idling. Overheating damages engine parts and causes expensive repairs.
Your vehicle’s cooling fans are designed to ensure that as much air as possible is drawn through the radiator. This helps the engine stay at a safe operating temperature, regardless of how hot or cold it is outside. The cooling fan is also important for keeping the engine running smoothly and efficiently.
A malfunctioning fan can cause your engine to overheat, car radiator fan so it’s essential that you fix the problem as soon as you notice any signs of a bad fan. To help you, we’ve put together a guide to changing the cooling fan motor on most cars. It’s not difficult to do and you can usually find replacements at your local Natrad store. Whether you have an electric or mechanical fan, this guide will give you the information you need to change the motor.
2. Clutch
Like most automotive parts, the cooling fan clutch will eventually wear out. While there is no hard-and-fast mileage at which this part will fail, it’s important to recognize the telltale signs of a worn clutch, so you can have the issue rectified by your mechanic before it leads to failed engine cooling and reduced power output.
A bi-metallic clutch is used to engage and disengage the engine cooling fan, which operates based on underhood temperatures. When hot air blows across the radiator, it heats up, which in turn causes a thermal spring in the front of the fan clutch to expand and open valve ports inside the clutch. This allows the heavy silicone fluid stored in the clutch to flow through the openings, locking the fan onto the pulley. As the temperature cools, the bi-metallic fan clutch closes and disengages the fan.
A mechanical fan clutch can be found in older vehicles, and it is usually mounted on the water pump car radiator fan pulley on a RWD car or the crankshaft pulley of a front-wheel drive vehicle. When the fan clutch fails, it may freewheel, leading to overheating and a loss of performance, or it can lockup causing noise and vibration. Nissens offers a wide range of quality aftermarket fan clutches that are designed and tested to ensure long-life operation and high levels of modulation for improved fuel efficiency, lower noise and less strain on the engine.
3. Coolant
When your car engine burns fuel, it produces heat that needs to be carried away. The coolant in your car takes the heat and transfers it to air that flows through the radiator, where the cooling fan is located. If the cooling fan motor or fan stops working, your engine can overheat. That can cause significant damage that requires expensive repairs.
Your radiator fan won’t run unless it gets a signal that the engine temperature has reached a specific level. The fan is usually activated by the engine control unit, which receives a signal from the coolant temperature sensor. If the coolant temperature sensor doesn’t function properly, the fan won’t turn on, and your car’s engine can overheat.
The radiator fan draws very little power, but it does have a fuse that can blow if there’s an electrical surge. If the fan fuse blows, it needs to be replaced immediately to keep the cooling system safe from further damage.
Your car’s cooling fans can also fail due to faulty wiring or the fan itself. If you’re not sure which of these issues is at fault, visit a Natrad mechanic near you for professional advice and repairs.
4. Temperature Sensor
Most modern cars have an electric radiator fan that draws power from the vehicle electrical system. These fans are very sensitive to temperature and can be easily triggered to turn on and off as needed. Unlike the mechanical fan clutch on older vehicles, modern fans usually don’t have many parts and therefore are less prone to breaking down. However, there are still problems that can occur from time to time.
A common reason why your car’s cooling fan won’t activate is because of a bad sensor. The sensor is a device that reads the engine’s temperature and sends a signal to the fan to come on based on the coolant temperature. The sensor can be built into the engine control module or it can be a separate part. If the coolant temperature sensor isn’t working, it can lead to overheating and other issues with your car’s engine.
Another reason the fan might not be turning on is because of a blown fuse or a bad relay. These are both easy fixes and can be checked by checking the owner’s manual for the location of these fuses or relays. Also check the wiring connections at these devices for signs of corrosion. Finally, you can try bridging the radiator fan relay with your multimeter and see if that starts the motor.