Why does my cooling fan stay on all the time?
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 does my radiator fan not turn 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.
What can cause radiator fan to keep running?
Here are some possibilities causing the fan to stay running longer.
- low coolant level,
- faulty coolant temperature sensor,
- PCM or ECU defective.
- coolant leaks from the water pump,
- cracked radiator,
- worn upper or lower radiator hoses,
- leaky heater core,
- leaky thermostat housing,
Is it bad to have radiator fans on all the time?
An electric fan SHOULD NOT run all the time. A mechanical fan WILL spin as long as the engine is running, but it will only ‘lock up’ when needed. To avoid a further rise of temperature, the fan induces air flow. The fan turning on is normal and a consequence of the hot coolant, not a cause.
Should radiator fan turn on when AC is on?
When the AC compressor is activated, it is actually expected that the radiator fan runs. For instance, the radiator fan is needed when the temperature sensor of the cooling fluid in the lower tank reaches approximately 212F.
How do I know if my cooling fan relay is bad?
Bad Cooling Fan Relay Symptoms
- 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 faulty cooling fan switch?
Bad Cooling Fan Relay Symptoms
- 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.
When should the radiator fan kick on?
A temperature-sensitive switch functions to turn the fan on and off periodically. Radiator fans are designed to start when the temperature of the engine coolant reaches around 200 degrees Fahrenheit.
Why does the radiator fan turn on when the AC is on?
The A/C requires the fan to run as part of the heat exchange process. The A/C runs on a separate circuit and is triggered by A/C system. The engine cooling system is normally triggered by the temp control sensor/sending unit or ECM/PCM depending on system, but virtually works under the same premise.
How do you check a fan relay?
How to Check a Fan Relay
- Look at the markings on top or side of the relay case and locate the two control circuit terminals, which connect to the relay’s coil, and the two power circuit terminals, which let electrical current pass to the fan.
- Connect the leads of an ohmmeter to the power terminals on the relay.
Should radiator fan turn on and off?
Your radiator fan should kick in at about 200 degrees Fahrenheit. If you notice your vehicle is overheating or at the very least running hotter than it normally does, listen for the fan to see if you can hear it.
How do you test a Thermo fan switch?
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. If the resistance does not change to zero, then the switch is bad.
Why does your radiator fan keep going on and off?
Here are some possibilities causing the fan to stay running longer. low coolant level, faulty coolant temperature sensor, PCM or ECU defective. coolant leaks from the water pump, cracked radiator, worn upper or lower radiator hoses, leaky heater core, leaky thermostat housing,
What causes the radiator fan to stay on?
If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times. Depending on the wiring setup of the vehicle, this may cause them to stay on even when the vehicle is off, which will drain the battery.
Should the radiator fan be running all the time?
This can lead to overheating, especially when the vehicle is at a stop, where there is no forward motion by the vehicle to pass air over the radiator. 3. 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 your radiator fan not running?
The most common causes when a radiator fan is not coming on is broken fuse, bad wirings, bad coolant temperature sensor, bad fan relay, or a faulty radiator fan . Here is a more detailed list of the most common causes of a radiator fan not coming on.
