Common questions

What happens if the cooling fan relay is faulty?

What happens if the cooling fan relay is faulty?

If the cooling fan relay is faulty, the cooling fan can continue to run unnecessarily, even when the ignition is off and the engine is cold. Conversely, the cooling fan may not run at all causing the engine to overheat.

What to do if your car relay switch is not working?

Remove your car’s dashboard, as this is the main site of the relay switches, and then turn your car on. By putting an end of an alligator clip to a grounded spot, you will then touch a wire of the relay switch with a multimeter. Record the measured voltage, and if it is not the right amount, then your relay switch is working poorly.

Why does the radiator fan not come on when the AC is on?

In order for the AC Condensor to do its job it must stay as cool as it can. As for the engine coolant temp sensor, if the coolant is not hot enough to make the fan come on, then there is no need for the fan yet and there is no problem.

Where is the relay on a radiator fan?

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. Testing a 4 pin relay is often very straightforward. Remove the relay and give 12 volts to pin 30 and 85. Ground pin 86 and check if there is voltage coming out from pin 87.

How does the cooling fan relay work on a car?

The cooling fan relay is the relay that controls the engine’s cooling fans. When the correct parameters are met, a temperature switch or the computer will activate the relay, which will allow power to the fans. The relay will usually be activated once it is detected that the vehicle’s temperature…

What should I do if my heater relay is not working?

Turn on the key and try the blower. Some relays may not activate until the car is running and have a built in delay so you may need to start the engine and wait a few seconds to see if your repair was successful. Depending on what you drive, this job could be a breeze or a nightmare.

Can a bad coolant sensor cause a car to not start?

Some cars use the engine coolant temperature sensor to control the electric cooling fans. You have two separate temperature sensors for the fans, dashboard gauge, and engine management in most cars. However, if your car has a single sensor, a bad engine coolant temperature sensor may result in your fans won’t start at all.

What are the symptoms of a bad cooling fan relay?

1. Engine running hot One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly.

Author Image
Ruth Doyle