Why is my Radiator Fan Not Working? 7 Reasons Why Radiator Fan Is Not Working & What to Do?

You may already be familiar with the functions of your radiator and cooling system.

The radiator cools down quickly when the wind blows through it. However, if the speed limit is not met, then the radiator will be cooled by the airflow. The radiator fan helps to keep the coolant down.

The radiator fan may fail, and your vehicle will overheat.

Why does the radiator stop working?

It is possible for a radiator to stop working due to problems such as a bad relay or fuse. You can also have a bad coolant temp sensor or low coolant level, as well as damage to the radiator fan.

Although these may be some reasons for your radiator fan not turning on, they aren't all. Below is a list of common reasons why a radiator fan won't turn on.

7 Reasons why your Radiator Fan Does Not Work

1. Blown Fuse

The fuse protects almost all electrical components in cars. A fuse protects electronic equipment from damage if there is an electric surge towards it. The fuse can also be called a "blown fuse".

It is not a big deal to replace a blown fuse. If your car’s radiator fan is non-functional, check your car’s user manual and locate the fuse for the radiator fan controller or the fan.

A fan uses an average 50A fuse, and a smaller fuse for the fan control module. Remember that if the fan fuse is blown – there might be a problem with the wirings or the radiator fan.

2. Faulty Temperature Sensor

You may have two systems on different models of a car. You can either have your fan control integrated in the engine control unit or a separate module. The temperature sensor is used by both control units to tell when to turn on the radiator fan.

The temperature sensor can be damaged and the controller will not know when the fan should start.

Some vehicles have separate temperature sensors to monitor the coolant temperatures of the radiator fan, and also the engine control unit.

To ensure that the temperature sensor is functioning, you will need to verify the information in your manual.

3. Poor connection or broken wire

The fan may not work even when it is hot, this could be due to a problem with the wiring or bad connections.

Verify the wires that connect to the radiator fan via the relay control unit. For corrosion signs, inspect the connectors. Check the connections at the control unit and relay for corrosion.

A multimeter can be ineffective for measuring the wirings. You need to place a load onto the wires to verify that they work. You can test the power supply to your radiator fan with a multimeter, but this is a quick check.

4. Lack of Coolant

You can get coolant in your system if it is too low. The coolant temperature sensor may not be able to read coolant temperature accurately. Low coolant levels should be topped up.

Failure to comply could result in your engine being seized and overheated. If you don't have the money to pay a lot, there is no way back.

5. Broken Radiator Fan

Faulty radiator fans could also cause problems with your radiator fans. They have an electrical motor inside, and they will begin to wear after a few years.

The easiest way to test electrical radiator fans is by using a wire that comes from the car. Unplug your radiator fan connector and plug in 12v+ or ground. This method is fast and easy to test radiator fans.

6. Faulty Fan Relay

The radiator fan draws so much power that there are often relays to power the coolant fan. This relay may become damaged and cause the fan not to turn on.

The fan relay is often located in the engine bay’s fuse box, but the best way is to check your repair manual to find where it is located.

A 4 pin relay can be tested easily. Turn off the relay, and supply 12 volts from pin 30 to pin 85. You can ground pin 86 to check for voltage at pin 87. Even better, connect pin87 to something drawing a lot power like the fan.

7. Bad Fan Controller Module

Some cars include a separate control module that controls the fan speed. It is located inside the engine bay where it can be exposed to dust and heat. The corrosion can eventually cause the control panel to malfunction.

Check for visual damage outside the relay. It is possible to open the relay and inspect for corrosion or bad soldering. If you find any issues, replace it.

Questions about Radiator Fans