The electric radiator cooling fan assembly is controlled by a thermoswitch located in the side of the radiator. At higher coolant temperatures, the switch closes to start the cooling fans. Any time the coolant temperature rises to higher than normal levels, the fan will start and continue to run until coolant temperature returns to a normal range.
Full Answer
How does a radiator fan work?
The definitive operation of the Radiator fan. The first things we need to know is the air flow over the radiator. belt driven off the water pump. Well Eurpoean folks took a longitudinal engine/tranny/driveshift/rear differential system and turned it sideways. directly infront of the engine. the invention of the electric radiator fan.
Where is the after fan run switch on the radiator?
Most of the after fan run are on the Low temp side of the switch in the radiator. if you run the a/c, it will run hotter, so they added a switch to the fan to turn it on, it is controlled by the heater control fan switch.
Why is my radiator fan not working when the car is hot?
If the fan is not working even when the car is heating up there might be a problem with the wiring. You need to inspect all the wiring leading into and out from the radiator fan. It is possible that a wire has worn out due to heat and needs replacement.
How to test radiator fans in a car?
You can test the electrical radiator fans by taking a wire from the car battery, unplug the radiator fan connector, and put 12v+ and ground into the connector. This is the fastest and easiest way to test your radiator fans. 6. Faulty Fan Relay
How does an electric radiator fan work?
Basically, a radiator fan blows cooler air through the radiator to lower the coolant temperature and cool off the heat from the car engine. Obviously, when the engine is running, it produces heat. That heat must be dispersed so that the engine will not experience any form of overheating or become too hot.
What controls the electric radiator fan?
The PCM controls fan operation; it uses the signal from the ECT or engine coolant temperature sensor. This sensor senses the temperature of the engine's coolant and sends a variable voltage signal to the PCM. The PCM operates the fan motor through the engine's cooling fan relay.
What controls electric fan on a car?
Electric fans generally are controlled by a relay, which in turn is controlled by the Engine Control Module (ECM).
How do I test my electric radiator fan?
10:3017:52Overheating Help! | Testing Cooling Fans - Relays - ConnectionsYouTubeStart of suggested clipEnd of suggested clipStart the vehicle and that will kick the high speed function on the fence. Now I specificallyMoreStart the vehicle and that will kick the high speed function on the fence. Now I specifically purchased these hundred fifty ohm capacitors to do this test.
Why is my electric fan not working?
Whether the blades aren't spinning or the fan is making tons of noise, most issues with an electric fan are caused by poor lubrication or blockages in the vents. To solve most problems with an electric fan, disassemble the fan, lubricate the central pin and bearings, and clean out the vent and motor case.
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.
What controls radiator fan speed?
In addition to the power, ground, and tach signal, 4-wire fans have a PWM input, which is used to control the speed of the fan.
Does the thermostat control the radiator fan?
The thermostat opens and closes when there is a need to. How it works is simple. When the temperatures outside are cold the thermostat stays closed and the coolant stays in the engine. When the coolant reaches the working temperature the thermostat opens and the coolant circulates through the cooling system.
How do you know if your radiator fan is not working?
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.
Are both radiator fans supposed to run?
On many vehicles, there may be two fans: a main cooling fan for the radiator, and a second fan for the condenser. Both fans should come on when the A/C is on.
How do I manually turn on my radiator fan?
0:155:42Installing a Manual Fan Switch for Electric Radiator Fans - YouTubeYouTubeStart of suggested clipEnd of suggested clipNow any car that has an electric radiator fan can be set up with a switch now the idea is to use theMoreNow any car that has an electric radiator fan can be set up with a switch now the idea is to use the switch to ground out one of the pins on the fan control relay.
Why won't my radiator fan turn on?
Here are the most common reasons that your radiator fan does not turn on: Before poking your hands around your fan, make sure to treat it like it still could come on, and and keep your hands out of its path.
What happens if your coolant is low?
Low Coolant. If the engine coolant level isn’t high enough to keep pressure in the engine it will run hot. But, there won’t be enough coolant to reach the temperature sensor. Without the coolant hitting the sensor, the temp reading will be significantly lower than the actual engine temp. Your CC’s radiator fan will not kick on.
Do fan clutches wear out?
Fan Clutch. Like any other clutch, a fan clutch will wear out over time. If everything else seems on the up and up, the springs in the fan clutch have worn past the point of proper function and can no longer do their job.
Can a CC radiator fan kick on?
Your CC’s radiator fan will not kick on. If you do have low coolant, don’t fill it up until the engine has cooled off. Adding coolant to a radiator dry enough not to trigger the engine temp sensor can cause problems from drastic temperature change. Let it cool down first.
How do MKIV fans work?
The mkiv fans have two speeds.... low and high. Both fans always work in tandem. The resistor pack inside the fans will burn out and the fans will stop working on low speed but will still work on high speed when the engine gets too warm. The a/c button turns the fans on LOW only, and the fans will still work on high if the engine temperature gets too hot, above 107C actually, or 224F. The only way to fix this is to replace the defective fan. Many times both are defective but the driver won't know until both fans stop working or only one fan is working and it starts to overheat in summer traffic.
Do MKIV fans work on high or low speed?
nitroscope8 said: The mkiv fans have two speeds.... low and high. Both fans always work in tandem. The resistor pack inside the fans will burn out and the fans will stop working on low speed but will still work on high speed when the engine gets too warm.
Why is my radiator fan not coming on?
Because the radiator fan is often drawing so much power, there is often a relay that is powering the coolant fan. Of course, this relay can get damaged, which will cause the radiator fan to not coming on.
How to test radiator fan?
You can test the electrical radiator fans by taking a wire from the car battery, unplug the radiator fan connector, and put 12v+ and ground into the connector. This is the fastest and easiest way to test your radiator fans.
Why won't my radiator fan start?
You probably already know the purpose of the radiator and the cooling system in your car. When you are driving fast , the wind is passing through the radiator to cool the coolant down without issues , but when you are driving slow , there is no wind pushed through the radiator.
What happens if coolant is low?
If your coolant level is low, there is a chance that you will get air in the system , and the coolant temperature sensor will not read the coolant temperature correctly. If the coolant level is low, you need to refill the coolant to optimum levels. Failing to do so could risk your engine becoming overheated and seized.
Where is the fan relay located?
The fan relay is often located in the engine bay’s fuse box , but the best way is to check your repair manual to find where it is located. Testing a 4 pin relay is often very straightforward. Remove the relay and give 12 volts to pin 30 and 85. Ground pin 86 and check if there is voltage coming out from pin 87.
Do radiator fans start when temperature sensor is broken?
In both cases, the control units use a temperature sensor to know when to start the radiator fan. If this temperature sensor is broken, the control unit will not know when to start the radiator fan. Some cars use separate engine coolant temperature sensors for the radiator fan and the engine control unit. You need to check your repair manual of ...
Can you test radiator fan wiring with a multimeter?
However, as a fast test, you can check with a multimeter if there is coming power to the radiator fan.
