How do you diagnose cooling fan problems?
Symptoms of a Bad or Failing Cooling/Radiator Fan Motor
- Cooling fans do not come on. The most common symptom of a faulty cooling fan motor are cooling fans that do not come on.
- Vehicle overheating. Another symptom of a possible problem with the cooling or radiator fan motors is the vehicle overheating.
- Blown fuse.
What controls the cooling fan?
The fans are controlled either with a thermostatic switch or by the engine computer, and they turn on when the temperature of the coolant goes above a set point. They turn back off when the temperature drops below that point.
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.
Is there a fuse 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. Keep area around the fan blade clear in order to avoid injury.
How can you tell if your thermostat is open?
Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.
Why are my cooling fans running at all times?
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.
How to troubleshoot an electric cooling fan problem?
Unplug the fan wiring connector. Closely examine the connector for corrosion or damage. If necessary, use electrical contact cleaner to clean the connector. Make sure the wires are firmly attached to the connector and not damaged. 2. Look at the polarity of the wires leading to the fan, identify power and ground (usually a black wire).
Why does my cooling fan relay stop working?
Cooling fan relays can stop working for any number of reasons. Common causes for relays failing to operate might be: Failure of the computer, temperature switch, or relay control module that turns the relay on or off. Ants in the relays (more common than you’d expect).
Why does my car a / C fan stop working?
The issue may stem from a malfunctioning cooling fan relay, wiring, or the fan itself. If the A/C Condenser fan isn’t working the A/C may stop cooling when the vehicle is in traffic and the “pop off” valve on the compressor may release the excessive high pressure due to elevated temperatures, making a loud noise and some mist from under the hood.