How to test a radiator fan relay with a multimeter?

If you’ve recently replaced your radiator fan, you might have noticed that there are no longer any fans blowing air across the radiator. There could be a simple reason why, and it’s likely that a fan relay has failed. A fan relay is a safety switch that ensures that the fan motor only operates when air is blowing across the radiator. If this fails, the fan motor will not run and your radiator will overheat

How to test a fan relay with a multimeter?

When a fan fails to spin, it’s usually due to a bad fan relay. There are two types of fan relays: power relay and sensor relay. While power relay is there to supply power to the fan motor, sensor relay is there to detect whether the fan is spinning If the fan is not spinning, the sensor relay tells the fan control board that the fan is not functioning. There are also contactless sensors available. They are usually placed at the fan blades. When the

How to test a radiator fan relay with an ohm meter?

Connect the red (COM) probe of your multimeter to the fan relay output and the black probe to the earth (ground). If the fan motor is working properly, the meter reading should be close to 0. If not, it means the fan motor is faulty. Connect the green probe to the input of the fan relay and the black probe to the earth (ground). If the fan motor is working properly, the meter reading should be near 0. If not, it means the fan motor is

How to test a radiator fan relay circuit with a multimeter?

If while driving the fan fails to turn on, it is likely that the fan motor is getting power from the fan motor circuit. If the fan motor is working properly, the fan motor circuit should have a 12 VDC power supply. So to check whether the fan motor is getting power from the fan motor circuit, you can use a multi-meter to test the fan motor circuit. First, connect an ammeter to the 12 VDC power supply line. Next, connect the ground connection of the

How to test a radiator fan relay with multimeter?

If the multimeter is giving you an error or flat reading, your fan relay is most likely faulty. If the fan is still running but the fan motor is making clicking sounds, it’s possible that the fan belt is broken. You can test this with a multi-meter by shorting the black (COM) and red (NO) wires together. If the radiator fan does not start at all or makes a humming sound, it’s possible you may have a bad fan motor