It’s normal for some vehicles to have a fan run for a few minutes after the car is shut off, generally to keep the engine cool. However, if the fan is running for an extended period,
the fan itself can become damaged due to overuse
. … It’s possible you may have a module or relay failing in your car.
Why does my cooling fan keep running?
Cooling fans stay on at all times
If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally,
it may cause power to be permanently switched on
, which will cause the fans to run at all times.
Why is my radiator fan not turning off?
Pull the cooling fan relay out of the box
. Replace the cooling fan relay with a new one. A stuck closed relay is the only thing that can operate the cooling fan continuously with the key off. The computer looses power with the key off and the same applies to the coolant temperature sensor.
How do I know if my cooling fan relay is bad?
- The engine runs hot or overheats. …
- The cooling fans don’t work. …
- The cooling fans keep running. …
- Warning lights. …
- Poor air conditioning performance. …
- Swapping Relays. …
- Measuring the Relay Coil’s Resistance. …
- Listening for Noises.
What are the symptoms of a bad thermostat?
- Leakage from the mounting surface. Appearance: Seepage, drips or large coolant bleed marks on or around the mounting surface or on the housing. …
- Rust and corrosion. Appearance: Rust and corrosion on the surfaces of the thermostat. …
- Deposit build-up. …
- Map-controlled thermostats.
Should radiator fan turn on when AC is on?
Both radiator fans should always run when the AC compressor is engaged. To check the temperature at which the fan comes on, turn the A/C off and keep the engine running until it reaches normal operating temperature. Most fans should come on when the coolant reaches
about 200 to 230 degrees
.
Why is my car overheating but it has coolant in it?
In general, it’s because
something’s wrong within the cooling system and heat isn’t able to escape the engine compartment
. The source of the issue could include a cooling system leak, faulty radiator fan, broken water pump, or clogged coolant hose.
How do you test a cooling fan module?
The quickest way to tell whether or not the electric fan(s) are working is to
start the engine
. Then, 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 tells the cooling fan to come on?
The engine temperature should trigger the fan to turn on
. It will also turn the fan off once the engine has cooled to under 200 degrees. You may have heard of a part called the radiator fan switch or temperature fan switch. This is linked to a thermostat and works much like your home’s HVAC system.
Can a bad thermostat cause radiator fan not to work?
Broken Thermostat
Thermostats are known to go bad and cause all sorts of cooling issues. … If this thermostat doesn’t open when the engine reaches the working temperature, the coolant will stay inside the engine block and the engine
will start to overheat
. This will result in the radiator fan not working.
How do you check if cooling fans are working?
- Determine whether your radiator fan is manual or electric. …
- To check an electric radiator fan, start the car and let it get up to the temperature where the fan normally kicks on.
- Use the volt meter to test if there is power to the wires. …
- Normal voltage for a radiator fan is around 12 volts.
What will a bad thermostat cause?
When the engine’s temperature rises very high, the thermostat opens and allows the coolant to flow to the radiator that reduces its temperature. … A bad
thermostat can stuck-open or stuck closed
. A stuck-open thermostat can prevent the engine from getting heated enough to function properly.
What happens if you run a car without a thermostat?
If you drive your car without a thermostat,
it will run at 50 degree centigrade
. When the car drives at this temperature, moisture or humidity will form. And when it is condensed, it will mix with oil and turn into slush (watery ice). This slush blocks out lubrication.
How hard is it to change your thermostat?
Upgrading to a thermostat that automatically changes the indoor temperature setting is fairly easy, and it can trim about
$180 off
your annual heating and cooling costs, according to the EPA. Simple models that only control heat are sold at home centers for around $25.
What if the radiator fan turns on only when the AC is on but overheats when is off?
The most likely culprits are a
thermostatic switch, fan resistor, temperature switch, low-speed or high-speed relay
, or a wiring issue. … When the vehicle has the AC on, the engine needs extra help cooling so the ECU commands the fan to be on any time the AC is on.
How long does it take for the cooling fan to turn on?
This typically takes
about 15-20 minutes
for the engine to reach the right temperature for the radiator fan to turn on in older cars. If there’s a problem with the engine’s temperature, then this can damage the radiator.
