This system is linked to the thermostat and works just like the HVAC system in your home. If either of these components fails – your radiator fan turns on continuously and this causes serious problems. The function of a fan switch is similar to the coolant temperature sensor work.
Radiator fan running high may not only be because of a bad thermostat. It may be the hoses, the radiator, heater core, water pump, thermostat housing, head gasket, freeze plugs, automatic transmission oil cooler, or cylinder head(s).
In many modern cars, the engine control unit (ECU) monitors the temperature, and if it detects that the engine is still too hot after shutting down, the fan will stay on until the temperature lowers to a safe level. This is particularly common after driving in hot weather or if you've been sitting in heavy traffic.
Possible causes of cooling fan not shutting off: faulty relay, PCM(powertrain control module), ect (engine coolant temperature) sensor, or low coolant level.
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.
There are two settings on your thermostat to control the fan – auto or on. AUTO means that the fan turns on automatically only when your system is heating or cooling air. Once the thermostat reaches the desired temperature, the entire system shuts off until the next cycle.
If your fan limit switch is set to AUTO but the fan continues to run without ever stopping, you'll need to call a professional. Two problems that could cause your fan to run without stopping include: A bad fan limit switch that needs to be replaced. Bad thermostat wiring.
Incorrect settings on your thermostat or fan limit switch can cause the fan to run continuously. Faulty wiring or a broken fan limit switch can also cause your fan to keep running. You can diagnose and fix some furnace fan issues on your own. Faulty wiring or a broken switch will require professional repair.
Why Is My AC Fan Not Spinning? In short, common issues that can cause an air conditioning unit fan to stop spinning are electrical issues, problems with the capacitor, contactor issues, a burnt out air conditioner motor, a broken fan belt, or clogged air filter.
Common causes for fans not turning off when they should include faulty thermostats, bad wiring, and stuck relays.
Scan your computer for malware
Malware (virus, spyware, trojans, and so on) can cause a computer fan to run constantly due to an overload on the processor (CPU), this in turn causes the fans to run constantly and fast. Spyware and other types of malware are a big cause of many computer problems.
The coolant temp sensor is the one the commands the radiator through the ecu . once the coolant temp sensor reads above 185–200 degrees the ecu will signal the radiator fan to engage in the on position until ideal temperature is achieved then will shut off.
Typically this would occur if something like the coolant temperature sensor is not reading correctly, or the thermostat is not functioning as intended.
AC Refuses to Start or Stops Suddenly: A thermostat that's not working correctly might fail to initiate the cooling cycle or might randomly shut off the AC. This erratic behavior can be due to electrical issues or miscommunication with the AC unit.
A bad thermostat can also cause the fan to run continuously or not turn off when it should. To ensure your thermostat is functioning correctly, it is recommended to consult with HVAC Alliance Expert's specialists.
The Fan Limit Switch is in Manual Override Mode
This will ensure that your furnace fan runs only when necessary and not continuously. The fan limit switch is typically located near the blower motor or in the control box. It just requires a press from your finger to behave accordingly.
This is the normal setting for a system fan. The On position will turn the fan on to run continuously, regardless of whether the heating or cooling system is turned on by the thermostat or not. This is the setting used to move air in your application all the time instead of when the system is running.
Leaving the fan running reduces wear and tear on the motor since it's not starting and stopping repeatedly. It's also beneficial to boost filtration, but leaving it on this setting has more drawbacks than benefits. When it runs nonstop, the fan consumes more energy, and the air filter needs frequent replacement.
If the control board is faulty or malfunctions, it may not send the signal to the fan to tell it to shut off. The same can also happen if the wiring between the control board and the fan is damaged or there is a loose electrical connection.
Keeping your thermostat fan set to "ON" may seem like a great way to circulate air throughout your home or office, but it actually has some disadvantages. Using this setting does lead to more energy consumption, as the blower's motor runs more frequently - you may notice slightly higher energy bills.
So, once the target indoor temperature is met, the thermostat will signal the heating or cooling system, as well as the fan, to turn “off.” With the “auto” fan setting, you can expect to conserve energy and lower energy bills (because your system fan is not constantly running and constantly using energy).
In most systems, the Y or Y1 wire controls your cooling system. If you have a heat pump, your Y or Y1 wire controls your compressor. Your compressor is responsible for heating and cooling your home. The G or G1 wire controls your fan.