233 Answers One cooling fan runs when the engine reaches a certain temp. The second cooling fan is designed to run when the a/c is turned on, providing more air flow throw radiator. However, it will cause no harm or damage if both fans run at the same time, with or without the a/c turned on.
Full Answer
Why does the case fan only start when cooling is necessary?
The case fan only starts when cooling is necessary? Case fan should be operating at all times, unless it is controlled by a PWM controller either from a separate pwm controller, or if the fan is connected to the mobo and the bios has the ability to control it. If it isn't spinning the bearing likely died and the fan needs to be replaced.
Do the a/C fan and heater work separately?
They work separately, unless the car is hot, then they both come on. Does the A/C fan even work? Turn on the A/C to see if it does come on.
Why does my car have two a/C fans at once?
Obviously if the car is designed for two fans to run at once, then it's not getting enough airflow at standstill and that causes my car to overheat. But if it is supposed to be that way, that means it's something else. They work separately, unless the car is hot, then they both come on. Does the A/C fan even work?
What causes the fan to run all the time?
I will keep you posted shortly- There are just too many to list.... That 4-pin refrigerant pressure switch was a common failure on the A3 cars, and its failure mode would cause the fan to run constantly. Never seen it manifest itself in the same manner on an early A4 car, though, but that doesn't mean it couldn't happen.
Should both cooling fans be on at same time?
Both fans should come on when the A/C is on. If one or both fans fail to come on, the lack of additional cooling provided by the fan may cause poor A/C cooling performance, and it may cause the A/C compressor to overheat and fail.
How do dual radiator fans work?
Dual Radiator Fan- dual fans are assembled in two's. They operate together to move air through the radiator core, providing a more effecting cooling effect. Dual radiator configurations are suitable for large engines that need a higher CFM rating.
How can you tell if a fan relay is bad?
Keep a lookout for the following 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.More items...•
When should the cooling fan come on?
To check the temperature at which the fan comes on, turn the A/C off and keep the engine running until it reaches normal operating temperature. Most fans should come on when the coolant reaches about 200 to 230 degrees.
Can you drive with one radiator fan not working?
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.
Do radiator fans run all the time?
Radiator fans are temperature controlled. They cut in and out to maintain the engine temperature at the optimum level where maximum efficiency is reached. Usually, the radiator fan will not start up the moment you fire up your engine.
How do you test a cooling fan?
0:0017:52Overheating Help! | Testing Cooling Fans - Relays - ConnectionsYouTubeStart of suggested clipEnd of suggested clipStart the air conditioning. Once you start the air conditioning the low-speed fan should turn on inMoreStart the air conditioning. Once you start the air conditioning the low-speed fan should turn on in other words these fans should kick on but it's at the low speed setting.
Can a bad thermostat cause radiator fan not to work?
If this thermostat doesn't open when the engine reaches the working temperature, the coolant will stay inside the engine block and the engine will start to overheat. This will result in the radiator fan not working.
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.
How do you check if cooling fans are working PC?
The fastest way to tell if your computer's fan has stopped working is to visually inspect it. If it's a desktop computer, you can usually see the fan rotating on the back of the case. If the fan is not moving, you must replace it immediately, before using your computer further.
Why one of the cooling fan is not working?
The most common reasons a radiator fan is not working are luckily due to a blown fuse, 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.
Does the coolant temp sensor control the fan?
As the control system receives the temperature from the CTS, it may trigger the cooling fan to either shut off or turn on. Additionally, it may signal the need for a richer fuel mixture or open the exhaust gas recirculation.
Why does my 20 amp fuse blow?
However, keep in mind that although any fuse can fail due to an inherent defect, it's far more likely that the 20 Amp fuse blew due to an overload at some time. The only load on that circuit is the fan motor.
Where should fuses and relays be located?
The fuses and relays should be in the vicinity of the engine compartment fuse box. If both fuses check good (with a meter) or are replaced without any change, then swap the two relays, and see if the non-operating fan now works. If so, then the relay is bad. (Probably best to replace both.)
Do 2003 AC fans turn on?
Both fans should turn on with the AC compressor, except at some higher vehicle speeds. The 2003 fan motors are single speed, and are run only at one speed. Each fan has it's own fuse and control relay. The relays are switched on or off by the ECM.
Can a 2.5 liter engine run in red?
Best to avoid overheating -- not good for the 2.5 liter engine. The fans can be tested by turning on the AC even when the engine isn't fully warmed up -- both fans should run (see chart above), so no need to run the engine into the red.
Why does my Cooling Fan Keep Running After the Car is Shut Off?
The cooling fan in your car keeps running long after the car is shut off due to a overheating or fault with the relay.
Why Does My Radiator Fan Not Turn Off?
The radiator fan might not turn off due to a faulty radiator control module, issues with the cooling fan, or the temperature sensor. You can easily identify what is causing this issue by following a few simple steps.
How Long Should A Car Fan Run After The Car Is Turned Off?
The consensus is 5 minutes as to how long the car fan can run after the car is turned OFF. This usually varies from model to model and for how long the car has been driven.
Should The Radiator Fan Be Running All Time?
No, the radiator fan shouldn’t be running all the time. It should run only when the engine is started and not after the engine is shut OFF.
How Often Should The Cooling Fan Come On?
The engine cooling fan should come ON when the engine has been idling for more than 20 minutes.
Should The Radiator Fan Turn On When AC Is On?
Yes, the radiator fan that is connected to the AC system should turn ON as soon as the AC is ON. The AC works to keep the car cool.
How Do I Know If My Cooling Fan Relay Is Bad?
The first sign of a bad cooling fan relay fan is an abnormal temperature rise in the temperature gauge. If the temperature shoots up too fast and goes above the normal limit, then it could indicate an issue with the cooling fan relay.
How to tell if a fan is bad?
You can usually tell by manually spinning the fan either direction with your finger while it's off. If it doesn't "wiggle" as it comes to a stop then the bearing is bad. Spin a fan you know is good and watch it as it comes to a stop and you'll see what I mean. Hard to explain.
Do case fans need to be on all times?
Case fan should be operating at all times, unless it is controlled by a PWM controller either from a separate pwm controller, or if the fan is connected to the mobo and the bios has the ability to control it.
