What causes radiator fan to keep running?
- ow 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,
- rusted coolant bypass pipe,
- bad radiator fan relay,
What could cause a radiator fan to not work?
- If the fan doesn't work with direct battery power, examine the terminal that plugs to the radiator fan connector. Look for corrosion and damage. ...
- Check for any blown fuses or a tripping breaker. ...
- If the fan doesn't come on at all, or runs noisy or at an abnormally low speed, replace the fan motor.
How to troubleshoot radiator fan not working?
Visual Check
- Fuse Whenever something electrical doesn’t work, the first thing to check is the fuse. ...
- Fan Wires If the engine is heating but the fan isn’t kicking in, check the fan wires. Start by unplugging the wires. ...
- Temperature Sensor The temperature sensor determines when the radiator fan comes on by reading the cooling system temperature. ...
How to manually turn on a radiator fan?
- Using the ratchet and 10 mm socket, disconnect the red 12V power lead from the battery.
- Release the fuse box by pulling out the plug holding it down toward the front of the car. ...
- To disconnect the bottom, use a flat screwdriver to release the tabs all around it. ...
Should radiator fan turns on and off constantly?
If there is a problem with the cooling system, it can cause the fan to turn on and off constantly. This can be due to a clogged radiator, a faulty water pump, or a leak in the system. If you are experiencing problems with your radiator fan turning on and off constantly, it is best to have it inspected by a mechanic.
Why is radiator fan always on?
The situation when the car radiator cooling fan keeps running constantly can be caused mostly by a failing coolant temperature sensor or its wiring, broken fan start relay, damage to the electrical wires, and electronic engine control unit (ECU) problems.
Do cooling fans stay on all the time?
Cooling fans stay on 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.
When should your radiator fan turn on?
about 200 degrees FahrenheitYour 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.
Why radiator fan keeps running after car turned off?
This is absolutely fine and normal. The reason behind this is quite simple . After turning the engine off, the ECU unit tells the fan to continue running as the coolant is still hot. Until the temperature comes down to normal, it keeps running which makes a bit of sound.
Does radiator fan come on with AC?
Q: Should the radiator fan run when AC is on? Yes. Both the radiator and condenser cooling fan are expected to turn on the moment you switch on the air conditioning system. For instance, it is expected for the cooling fan to switch on when the engine carries loads or once it reaches the normal operating temperature.
How can I tell if my radiator fan is working?
A simple way to check if the radiator fan is working is to start your engine and turn the air-conditioning system (A/C) to the maximum speed. If the fan is spinning, then it means that the fan motor, fuse, wiring, and relay are all working properly.
Why does my radiator fan not turn off?
Low Coolant Level If the fan in your automobile continues to run even after you have shut off the engine of your vehicle, then the coolant in your car may be too low. The water pump is a potential source of leaks and when these leaks occur, your coolant reduces, and this may cause your fan to keep running.
How do I know if my radiator fan is bad?
These are the most common signs of a faulty radiator fan assembly in need of replacement:Engine Overheating. When the radiator fan isn't functioning properly, it is not able to adequately cool down the car's engine. ... Air Conditioner Function Diminished. ... Loud Noise Coming From Radiator Fan.
What sensor turns on the radiator fan?
coolant temperature sensorOn most modern cars, the cooling fan is controlled by the Engine Control Unit (ECU) which gets a signal from the coolant temperature sensor. If it's not working, the fan won't turn on when it needs to, which means the engine might overheat.
Why does my radiator fan not turn on?
The most common reasons why a radiator fan is not working are due to a blown fuse, a bad relay, or a broken wire. It can also be caused by a faulty coolant temp sensor, low coolant level or the fan itself can be damaged.
Can you drive without a radiator fan?
Yes, you can drive your car without a radiator fan, but you never should. Your vehicle's cooling system is crucial to its performance, and every time your engine overheats, you cause damage.
Why does my radiator fan not turn off?
Low Coolant Level If the fan in your automobile continues to run even after you have shut off the engine of your vehicle, then the coolant in your car may be too low. The water pump is a potential source of leaks and when these leaks occur, your coolant reduces, and this may cause your fan to keep running.
How do I know if my cooling fan relay is bad?
Bad Cooling Fan Relay SymptomsThe 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.More items...•
What are the symptoms of a faulty cooling fan switch?
Common signs include engine overheating, the Check Engine Light coming on, and a broken or shorter signal wire.
Why does cooling fan come on when engine is cold?
The cooling system thermostat is designed to quickly bring the engine up to operating temperature. If stuck closed, the result would be the engine overheating in a short time. The cooling fan on while the engine is cold could be normal if the A/C is on.
Why do radiator fans turn on?
The radiator fan is programmed to turn on once the car is above operating temperature to add airflow to the engine drawing air through the radiator. This is especially important when sitting in traffic since there is not much airflow while the car is not moving.
How does a radiator fan work?
The ECU knows when to turn the fan on by the temperature sensor near the thermostat reading the temperature of the coolant and sends a signal to the fan relay.
How hot should the radiator fan be?
Most cars are programmed to operate at about 200F. The fan should kick on once the coolant gets above about 200F and cars are programmed to allow the fan to cool the engine even if the car is turned off if the temp is above 200F.
How long does it take for a car cooling fan to turn on?
Most thermostats open at around 185F and the fan should come on at about 200F. Generally this takes 10 to 15 minutes of idling.
Why is my car running hot and not cooling?
If your car is having trouble cooling and is running extra hot, it could be from a cooling fan not turning on at the right time. A car can also have difficulty warming up if the fan is running constantly. Both of these things happen when the smallest of the cooling system components goes bad and is very common, so here is how to resolve it!
How long does the engine fan stay on after you turn off?
No need to worry if you notice the engine fan stay on even after you park the car. This is normal and the fan may stay on for up to 10 minutes after the car has been turned off.
Why does my engine fan keep running?
You may have noticed the engine fan always on because your car is taking extra time to warm up. The fan always running will wear out the fan sooner and will prevent your car from warming up but will not harm anything besides this. Still it is a good idea to find the reason for the malfunction.
What happens if the radiator fan doesn't come on?
If there’s a problem with the engine’s temperature, then this can damage the radiator. Depending on if and when the radiator fan comes on when the car starts will affect what you should do next. If the fan doesn’t come on, you need to look for a broken fuse or breaker.
How to know if radiator fan is working?
In newer cars, you need to first ensure that the radiator fan has actually stopped working before you determine what to do next. You can do this by listening and feeling if the radiator fan turns on when the car starts. If you need to confirm if it’s in working order or not, you should turn on your engine and let your vehicle idle. Turn the air conditioning to the maximum setting – this should spark the cooling fan to immediately come on.
What Is The Function Of The Radiator Fan?
The engine contains a combustion chamber where explosions take place to provide power and heat the car. These explosions cause the engine to heat up extremely quickly and can sometimes lead to overheating. This is a reason why the radiator fan turns on when the car starts.
How does an electric radiator fan work?
The electrical radiator fan is controlled by an electric motor, with the radiator fan turns on when the car starts. The engine’s computer is in charge of when the fan turns on and off, dictating the radiator fan’s usage based on the temperature of the vehicle.
Why won't my radiator fan turn on?
If your vehicle is not operating the way it is meant to, then the radiator fan will not turn on when the car starts. If your car is running at a sub-par level, then there is a greater chance that other components can be negatively affected and lead to more repairs and replacements. A faulty mechanism can directly affect another cog in the machine, ...
What is the role of radiator fan in a car?
The radiator fan is in charge of pulling cool air through the car’s radiator, helping cool off the passengers and keep your ride as comfortable as possible. ...
Why does a fuse blow?
The fuse will blow to protect the rest of the system from further damage due to the unforeseen electrical surges. The cooling fan motors are crucial to the cooling fan assembly and play a huge role in your car’s safety, keeping the correct temperatures while idling and at low speeds.
How much of the time is a bad thermostat?
90% of the time is a bad thermostat.
What is the secondary circuit of a fan relay?
IIRC The fan relay's Secondary Circuit is "Normally On," and the fan switch is there to power up the relay's Primary Circuit, which then breaks the Secondary Circuit, and cuts power to the fan.
Is the thermostat at fault for OP?
You are spot on with what you and Mr Thread Ressurector point out though - no way the thermostat is at fault for OP's condition.
Is the thermostat on the list?
Yep, the thermostat is on the list since I have also a CEL P0125. I also know that code can be link to a bad O2 sensor.... but without catalytic converter...