What causes cooling fans not to come on?

What causes cooling fans not to come on?

Six things may prevent an electric cooling fan from coming on: Defective temperature switch, coolant sensor or other sensor. Engine thermostat is stuck OPEN (engine never gets hot enough to turn on the fan) Faulty fan relay.

How do you test a fan control module?

To test a fan motor, unplug the electrical connector at the motor and use fused jumper wires to connect battery power and ground directly to the fan. If the fan does not operate, replace the motor.

How do you test a cooling fan?

That’s why you will need to test it. Unplug the fan connector closest to the fan. Make up some jumper cables. Then connect them directly, from the battery to the fan motor, to see if it spins.

Should radiator fan run all time?

An electric fan SHOULD NOT run all the time. The fan turning on is normal and a consequence of the hot coolant, not a cause. The coolant may not be moving due to a water pump problem, blockage in the radiator or hoses, or a stuck valve, i.e., the “thermostat” in the coolant line.

When should my radiator fan kick on?

about 200 degrees Fahrenheit

What sensor controls the radiator fan?

coolant sensor

Which fuse is for the radiator fan?

The cooling fan relay is normally located in either the underhood fuse and relay center or mounted to the electric fan assembly behind the radiator. To replace the cooling fan relay, there are two methods that we will cover for the positions mentioned above.

How do you test a radiator fan sensor?

You can test the cooling fan temperature switch using a test light.

1. Connect your test light to battery ground.
2. Start and idle the engine, and backprobe the connector terminals with the test light.
3. Wait for the engine to reach operating temperature.
4. Now backprobe the other wire at the connector.

What are the signs of a bad temperature sensor?

What Signs May Signal Your Coolant Temperature Sensor May Be Failing?

• Poor Fuel Economy.
• Irregular Temperature Readings.
• Black Smoke from Your Exhaust.
• Your Engine is Overheating.
• Your Check Engine Light is On.

Does the radiator fan have a fuse?

A radiator fan is necessary to keep your car cool. The fuses inside of the radiator fan must be in good working order to make sure that the engine is able to stay cool. Without these components your car overheats. Over time this could create damage that is irreversible.

How can you tell if a fan fuse is blown?

Remove the fuse from its holder. In some cases you may need a small screwdriver to unscrew the fuse holder cap. Look at the fuse wire. If there is a visible gap in the wire or a dark or metallic smear inside the glass then the fuse is blown and needs to be replaced.

Where is the fuse for the radiator?

Some times it is located behind the glove compartment, sometimes on the lower, left end of the dash board. You may find another fuse relay list telling what each fuse is for. If not, you may find a diagram of the fuse box in the operator’s manual.

How do you diagnose cooling fan problems?

Symptoms of a Bad or Failing Cooling/Radiator Fan Motor

1. Cooling fans do not come on. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on.
2. Vehicle overheating. Another symptom of a possible problem with the cooling or radiator fan motors is the vehicle overheating.
3. Blown fuse.

Where is the cooling fan sensor located?

Usually, the location of the coolant temperature sensor will be located directly behind the coolant pipe. In most modern cars and vehicles, this is present behind the right cylinder head that is located right underneath of the air intake pipe.

How do you test a fan relay?

The quickest way to tell whether or not the electric fan(s) are working is to start the engine; let it reach normal operating temperature and then turn the A/C on. The cooling fan in the engine compartment should turn on to pull air through the radiator and A/C condenser.

What does the fan relay control?

The relay controls the engine’s cooling fans as well as the fan for the A/C condenser. It also saves electricity. Since excessive heat will damage the vehicle’s parts over time, a bad relay must be replaced as soon as possible.

How do I know if my blower motor relay is bad?

Here are some of the warning signs of a bad heater blower motor resistor:

1. Fan does not work at all, so no air comes out of the vents.
2. Fan only works on some speeds and not others.
3. Fan only works on the highest speed.
4. Fan runs all the time and can’t be controlled with the fan switch.
5. You see smoke coming out of the vents.

What happens when a blower motor resistor goes bad?

If you have faulty blower motor resistor you may experience low airflow coming from the vents even when the fan is all the way on high. In some cases bad blower motor resistor may not even turn the blower motor fan as a result your fan will not work at all and there will be no air coming from the vents.

What can cause a blower motor to stop working?

In some cars, a failed blower motor resistor can cause a heater fan to stop working completely. In most cases, a blower motor resistor fails due to corrosion or overheating. In most cases when a blower control module fails, the blower motor doesn’t work at all.

Where is the blower motor reset button?

Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.

How do I know if my fan motor is bad?

5 Signs That Indicate a Failing AC Fan Motor

1. The fan won’t start even though the AC is on.
2. The fan continues to run, even when shutting off the AC.
3. The fan is on but rotating very slowly.
4. The fan runs intermittently.
5. There’s a rattling or buzzing noise coming from the condenser unit when the fan is turned on.