Radiator fan not turning on automatically

What causes the radiator to stop working? The most common reasons a radiator fan is not working are luckily due to a blown fuse, bad relay, or a broken wire. It can also be caused by a faulty coolant temp sensor, low coolant level or the fan itself can be damaged.

Should radiator fan come on when car starts?

Should My Radiator Fan Come On When I Start My Car? A fan should start to turn on as soon as the temperature of the engine reaches a certain temperature.

What sensor controls the radiator fan?

coolant temperature sensor

On most modern cars, the cooling fan is controlled by the Engine Control Unit (ECU) which gets a signal from the coolant temperature sensor.

Do car fans turn on automatically?

Engines operate at their most efficient when they’re hot but not too hot. The fan turns on when you’ve stopped driving because no more cooling air is flowing into the engine bay. This causes the temperature to rise, automatically triggering the fan.

What tells the cooling fan to come on?

On most systems, there is a coolant temperature switch, that turns the fans on and off. First, locate the coolant temperature switch and unplug it. But, be sure you have the right one.

Does temperature sensor turn on fan?

As the control system receives the temperature from the CTS, it may trigger the cooling fan to either shut off or turn on. Additionally, it may signal the need for a richer fuel mixture or open the exhaust gas recirculation.

How do I know if my cooling fan relay is bad?

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.

How do you test a radiator fan switch?

Turn on the burner and slowly increase the water temperature. The ohmeter should be turned on and have a reading of high resistance. When the water reaches between 180 to 220 degrees Fahrenheit, the switch should turn on and the resistance seen by the ohmmeter should change to zero.

Does the thermostat control the radiator fan?

The thermostat opens and closes when there is a need to. How it works is simple. When the temperatures outside are cold the thermostat stays closed and the coolant stays in the engine. When the coolant reaches the working temperature the thermostat opens and the coolant circulates through the cooling system.

Can a bad thermostat cause fan not to come on?

If the thermostat is stuck open (allowing coolant to flow) it can cause the engine to run cooler than normal so obviously the fan wouldn’t come on…..but not like the engine/coolant can be running too hot and the thermostat somehow effects the sensor reading or operation of the fan.

Can a coolant temp sensor cause fans not to work?

A faulty coolant temperature sensor may result in a fan not being properly used, which may cause the engine to overheat.

What is the radiator sensor called?

A coolant temperature sensor (CTS) (also known as an ECT sensor or ECTS (engine coolant temperature sensor) is used to measure the temperature of the coolant/antifreeze mix in the cooling system, giving an indication of how much heat the engine is giving off.

Does the thermostat control the radiator fan?

The thermostat opens and closes when there is a need to. How it works is simple. When the temperatures outside are cold the thermostat stays closed and the coolant stays in the engine. When the coolant reaches the working temperature the thermostat opens and the coolant circulates through the cooling system.

How does a fan control relay work?

The cooling fan relay is an electromagnetic switch that controls the power supply to the engine’s cooling fans. It ensures that the energy-intensive devices only run when needed, usually when the vehicle is immobile.

How do you test a radiator fan relay?


So you want to test AC. Relays. If you want to test grab this other one the cooling fan relays that we have here starter relays relays for actually you can hear it click well. Then. You hear that.

How do you test a radiator fan switch?

Turn on the burner and slowly increase the water temperature. The ohmeter should be turned on and have a reading of high resistance. When the water reaches between 180 to 220 degrees Fahrenheit, the switch should turn on and the resistance seen by the ohmmeter should change to zero.

Does a radiator fan need a relay?

Most parts stores carry toggle switches and/or push-pull switches that will handle anywhere from 30-60 amps, so that would work. If you’re using one of those thermostatically-controlled deals (or a low amp rated manual switch) you should use a relay.

How do you check a relay?

antennamediatorino.eu
So now that we check the resistance of the coil on the relay. We can actually energize it by adding power and ground to the terminal eighty-five two pins 85 and 86. And see if there really clicks.

Where is the cooling fan switch located?

The cooling fan switch should be located near the thermostat housing on the left side of the engine, behind the distributor assembly.