Every PC user should know how to check the fan on a laptop, because it is this component that prevents the entire system from overheating.
During normal use, laptop fans exhaust air and produce a soft to moderately audible sound. If your laptop's cooler is quiet, the air around the vents is calm, and your laptop is very hot, the cooling is likely not working.
Fans play a critical role in the longevity and functionality of a laptop. You should definitely replace a broken cooler immediately to avoid equipment failure.
Presence of sound
A properly functioning laptop cooler sounds like a fan with a soft propeller; however, it may not be heard when you first turn on the computer because it is running at the slowest possible speed.
To provide more airflow and cool the system, the fan speeds up as you continue to use the laptop. It will likely switch to a faster and louder mode after about five minutes when the laptop reaches operating temperature.
Laptops with better cooling may have incredibly quiet fans that are only audible in quiet rooms by attentive listeners. Please note that the fan may be broken or clogged if it makes irregular pulsating or loud noises.
How to organize PC ventilation. Quick Guide for Beginners
A question that sooner or later faces any PC owner is cooling. Overheating of components causes a decrease in performance, and in the worst case, it ends in processor degradation and chip failure. And vice versa - thoughtlessly hanging the case with fans can turn it into a real vacuum cleaner that will irritate household members with its hum.
The quality of the ventilation system depends on the type and number of fans, how they are connected to the motherboard and their correct location in the computer case. However, first things first.
Main characteristics of fans
Static pressure is the air pressure created by the fan. Depends on its design and the speed of rotation of the impeller. The higher this indicator, the better the fan works under conditions of high resistance (for example, when pumping air through a fine-mesh radiator).
Air Flow (CFM) - The amount of air pumped. Historical units of measurement were cubic feet per minute. Devices with CFM greater than 50 show effective operation.
Rotation speed (RPM) is the number of revolutions per minute. The more, the higher the performance (and noise). Most models do not exceed 2000.
Pulse width modulation (PWM, or PWM) - automatic adjustment of fan speed using the motherboard. Requires a 4 pin connector. Fine tuning can be done using special proprietary utilities.
ASUS Fan Expert
Fan thickness is usually about 25 mm. Thinner versions are available for small packages (HTPC), but are less efficient due to lower static pressure and CFM.
The type of bearing is an important characteristic on which the life and level of noise generated depends. In modern models you can find several types: from the cheapest plain bearing (with a low resource) to the most expensive and rare ceramic rolling bearing and bearing with magnetic centering. The golden mean in terms of service life, price and noise are turntables with hydrodynamic bearings.
Noise level - measured in dBA. The value comfortable for the human ear should not exceed 30 dBA. More fans does not mean noisier. More often than not, the opposite is true, especially if the fans are controlled by the motherboard, which controls the temperature of the components.
- 0–25 dBA - silent PC;
- 25–35 dBA - noise at daytime background level;
- 35–40 dBA - noticeable noise level (can be reduced by moving the computer under the table);
- 40 dBA and above is a loud and uncomfortable noise level.
Size matters
The size of the fan determines its performance and noise level. The larger the diameter, the fewer revolutions you need to make to achieve the desired effect and the quieter it works. Most often, the average user has to deal with fans of the following sizes:
92 x 92 mm is a fading format, to which case manufacturers are paying less and less attention. Comparable in cost to larger, more efficient fans.
120 x 120 mm - cheap and cheerful. The most common and universal. A good four-pin version can be bought within 1000 rubles.
140 x 140 mm is the ideal, according to the author, balance of noise and performance. The price for a decent model starts from 1000 rubles.
200 x 200 mm is a rare solution, but quite effective in terms of cooling and silence. The main problem is finding a replacement in case of breakdown. The second controversial point is the cost, which for famous manufacturers starts from four thousand rubles.
Some manufacturers build real monsters into their bodies.
It is worth understanding that choosing a case with fans of rare sizes can result in some problems if they break. If the case is designed for standard 120/140 mm turntables, it will be easier and faster to compensate for the loss. As practice shows, good 140 mm fans at 600–800 rpm or 120 mm fans at 800–1000 rpm will provide good results and maximum acoustic comfort.
Options for connecting fans to the motherboard. Connector types
Modern fans are connected to the motherboard via a 3- or 4-pin connector. The type of connection will determine whether you can control the fan speed programmatically. More exotic are the 2-pin connector (usually used in power supplies) and the 6-pin connector (with backlight control). Connecting fans directly to the power supply via Molex is considered obsolete.
For 3-pin models, the rotation speed depends on the voltage change. Speed monitoring is possible, but there is no PWM. Often such fans operate at higher speeds and make more noise.
For 4-pin models, the rotation speed is controlled by the motherboard using an additional wire. Modern BIOSes do an excellent job of automatically controlling fans; the main thing is to correctly set the temperature limits in the motherboard settings.
Most modern motherboards have 4-pin connectors, but 3-pin options are still found. If necessary, you can connect a 4-pin fan to a motherboard with 3-pin connectors and vice versa. The fans will operate at standard speeds.
You can also regulate the fan speed using the rheobass. But the era of such devices is becoming a thing of the past: in modern cases there is no place left for them, and their functions have been taken over by motherboards.
If there are more fans than connectors on the MP, special splitters are used. However, you shouldn’t get carried away with them: it’s better not to install more than two fans on one channel. Otherwise, you will have to provide them with additional power, which will lead to the appearance of extra wires in the case.
In any case, already at the stage of purchasing a motherboard, you need to understand how many turntables the future system will need. Despite the higher cost, preference should be given to 4-pin fans with the most advanced control method.
How many fans are needed and how to install them
The modern model of hull construction involves the creation of a kind of wind tunnel: cold air enters from the front, and hot air is thrown out through the rear and upper walls. Cases with fans on the side wall and on the bottom have almost disappeared from sale. Most often, manufacturers try to create excess pressure in the case (they install more fans for blowing), and this is not just like that. Firstly, hot air will be removed more efficiently, and secondly, less dust will remain in the case.
One fan is quite enough to cool an office-level system without a video card with some kind of Celeron, Pentium, Sempron or A10, where the TDP of the processor is around 50 W. The author prefers to install the fan on the blower, since the cooler on the processor will help with the release of hot air, especially if it is a tower type.
The location of the fan is shown schematically and depends on the type of case and the location of components in it.
Two case fans (one in the front, one in the back) can handle a combination like Ryzen 3 (Core i3) + GTX 1650 (RX 550).
Three fans (two in front, one in back) - an application for the middle level: Ryzen 5 (Core i5) + 2060 (RX 5500XT).
Four turntables will ensure normal operation for the Ryzen 7 (Core i7) + 2070 (RX 5600XT).
Everything changes when Her Majesty the Gaming Graphics Card comes into the case - the main heater of any gaming PC. To keep the heat dissipation of HEDT systems in check, in addition to a spacious case, you need five or six fans: two or three front fans for intake, one rear and two top fans for exhaust. Or a custom SVO.
Feeling the air
Even if you can't hear the fan running, the user should feel air coming out of the vents. The air flow may be very weak when the computer first turns on, but it increases as the system reaches normal operating temperature.
The laptop fan should then start pushing air out of the main exhaust port, usually located on one of the sides.
You can place the palm of your hand on the system, about half an inch from the vent, and feel the air flow. If your laptop is quiet and there is no air flow, the cooler may be broken.
If you can hear the fan running but only a small amount of air flow is felt from the vents, the cooler may be closed, in which case you should clean the vents with compressed air.
Error Watching
If your computer regularly restarts without warning, slows down during normal use, or displays the dreaded BSoD or Blue Screen of Death, there may be a problem with the fan.
The fan itself is attached to the radiator as part of the cooling unit, so even if it is pushing air, there may be problems with another part of the unit. The system can overheat if the cooling block fails or the thermal paste connecting the processor and the cooling block wears out.
Temperature check
Even if the fan is pushing some air out of the vents, it may still have a hardware problem, such as a motor problem, that is preventing it from cooling the computer sufficiently.
Some laptops display temperature readings when turned on. But if the PC does not provide such information, it is advisable to use a hardware monitor program to check the processor temperature.
If the program registers a constant temperature of over 70 degrees Celsius while the laptop is doing absolutely nothing, the fan may be broken.
Elimination of overheating
If the user is sure that the cooler works, but does not cope with its task, he needs help.
One way to help is to eliminate unnecessary processes. Mac users can isolate and kill unwanted processes using Activity Monitor, while Windows users can use Task Manager.
Linux users also have a number of options available for managing processes.
How to check the cooler on a laptop
Proper operation of the cooling system extends the life of the computer for a long time. If there are problems, parts begin to overheat and fail. If the equipment begins to “slow down” or becomes very hot, then first of all you should check the functionality of the cooler on the laptop.
Software check
The easiest way to find out the cause of problems and eliminate their consequences is to use programs.
On many devices, the Bios affects the activity of the cooler. This is especially true for expensive laptops, although there are exceptions.
IMPORTANT! If you have laptops from Acer or MSI, then you should take a closer look at this method.
Turn off your device and turn it on again. Once the boot screen appears, enter the Bios . This can be done using the Del, F2 or ESC keys. The combination depends on the model of device purchased.
Going to the main menu, select the Power , which is responsible for the temperature of the processor and cooler. Now you need to find CPU Q-Fan Control and CPU Fan Profile . It is important that the first indicator is active. The second parameter is responsible for the fan rotation intensity:
For Lenovo owners, this advice may not be relevant.
Using software
You don’t have to go into the BIOS menu and solve a potential problem in the usual way. To do this, you only need the Internet and the name of the desired program.
SpeedFan is an excellent application that allows you to determine the health of your cooler. Download it from the official source and install it on your PC.
As soon as you launch the program, you will see what the temperature is on the sensors. It will also be possible to manually change the cooler speed setting. To do this, uncheck the box next to “Auto-adjust fans” and write the required rotation speed, calculated as a percentage.
If the recorded number of revolutions is not suitable due to severe overheating, you can change the data in the “Configuration” section. The utility will automatically adjust to the selected value.
Another useful application is AIDA64 . It is preferable to use for those who enjoy heavy games, especially online.
If the temperature does not exceed 50 degrees, then the cooler is working properly. Exceeding this limit indicates existing problems.
Cooler hardware check
You can use a more difficult method - hardware verification. To do this, you will have to disassemble the laptop and diagnose the cooler manually.
Before removing the fan, be sure to read the instructions. If the warranty period has not yet expired, it is highly recommended not to disassemble the laptop yourself. The best solution in this situation is to turn to professionals.
If you do not want to visit a service center, you can make an independent attempt to diagnose. It is important to know that there is no need to completely remove the cooler. You only need wires for testing on another device.
To do this, you will need a USB black and red wires on the other . Follow this algorithm of actions:
- Connect the black wire of the cable to the black wire of the cooler.
- The red wire must be connected to the red one.
- Plug the USB into another device.
IMPORTANT! If the fan starts to rotate, then everything is fine. You may just need to clean the cooling system or replace the thermal paste.
To get rid of dirt, it is not necessary to resort to removing the cooler from the laptop case . It is enough to blow it out with a can of compressed air (in extreme cases, a vacuum cleaner will do). If there is too much dust, you can use a brush to remove it.
Then wipe the laptop with tissues or a cotton swab soaked in alcohol. This will increase the performance of the device even in the absence of a hardware problem.
If the methods described above do not produce results when you independently check the cooler for functionality, take your laptop to a service center. Professionals will certainly cope with the problem that has arisen!
Causes of malfunction on the VAZ-2114
- Fan motor malfunction . The problem is resolved by replacing it with a working one;
Replacing the fan motor
Changing the fan relay
Checking for an open circuit
Changing the coolant temperature sensor
Video about replacing the fan switch sensor
How does the fan sensor work?
The fan switch sensor itself is a temperature relay. Its design is based on a bimetallic plate connected to a movable rod. When the sensitive element of the sensor heats up, the bimetallic plate bends, and the rod attached to it closes the electrical circuit of the cooling fan drive.
A standard automotive voltage of 12 Volts (constant “plus”) is constantly supplied to the fan switch sensor from the fuse. And the “minus” is supplied when the electrical circuit is closed by the rod.
The sensitive element comes into contact with antifreeze, as a rule, directly in the radiator (in the lower part, on the side, depending on the car model), but there are engine models where the fan sensor is placed in the cylinder block, such as in the popular VAZ-2110 car (on injection engines). And sometimes the design of some engines provides as many as two sensors for turning on the fan, in particular, on the inlet and outlet pipes of the radiator. This allows you to both turn on and turn off the fan forcibly when the antifreeze temperature drops.
It is also worth knowing that there are two types of fan temperature sensors - two-pin and three-pin. Two-pin ones are designed for fan operation at one speed, and three-pin ones are designed for two fan speeds. The first speed is turned on at a lower temperature (for example, at +92°C...+95°C), and the second at a higher temperature (for example, at +102°C...105°C).
The temperature for switching on the first and second speeds is usually indicated directly on the sensor body (on the hexagon under the wrench).
Checking the functionality of the cooling fan motor
The easiest way to check the operation of the fan is to put two straight wires on it: minus and plus.
The plus is taken from the battery, the minus from the car body. If it doesn’t work when the circuit is closed, then that’s where the problem lies. When starting the blades, we look for the problem elsewhere.
Cooling fan operation diagram
Basically, when a non-working fan is detected, several reasons are identified:
- The electric motor is burnt out, there is a break in the winding;
- Wear of carbon brushes;
- The bearing has jammed or fallen apart.
If in the last two cases the problem is solved with little effort, so to speak, the first involves replacing the electric motor.
Important! When installing wires, the main power supply to the electric motor must be disconnected.
Procedure for checking
The operation of the fan on the VAZ-2114 is connected through 2 fuses. One of them is also responsible for the sound signal. You can check it by pressing the horn. If there is no sound, replace it with a whole one. It is located in the mounting block, it is 20 ampere, marked F5.
Check and, if necessary, change fuses
The second one is located under the dashboard, on the passenger side. Under the casing there are 3 relays with a fuse for each. The middle pair is responsible for the operation of the cooling fan. Replace the blown element with a new one (the fuse can be “ringed” with a multimeter or limited to a visual inspection. To check the functionality of the relay, you will need an ohmmeter). When checking their condition, at the same time make sure that the contacts are in normal condition, and if oxide is detected, clean them.
Important! If you find a blown fuse, you should not limit yourself to replacing it with a new one. It is imperative to find the cause of the break, since in the near future the new one will burn out again.
Checking the fan switch sensor
If the cause is not found, the next step should be to check the functionality of the fan switch sensor . It's not difficult to do this. Disconnect it and turn on the ignition, while paying attention to the fan. The rotation of the blades indicates that the cause of the problem is in the sensor.
Checking the cooling system fan switch sensor
Due to the fact that very often the sensor begins to fail, sending erroneous signals, it is recommended to check it in one more way . To do this, you will need a container with antifreeze or antifreeze, a thermometer and a multi-mert. Wires from the measuring device are connected to the sensor terminals, the threaded part of the sensor is immersed in the liquid. Heat the contents of the container to the temperature at which the fan operates (on a VAZ 2114 - 92 degrees). When the contacts close, the multimert will sound a sound signal. This means the sensor is working, if this does not happen, you can safely throw it away and buy a new one.
Healthy! Before installation, it is advisable to check the functionality of the purchased sensor in the same way.
Video about checking the cooling fan switch sensor
Final check
Having eliminated the problem, start the car engine. The fan motor should start after approximately 5 minutes of idling . If this does not happen, and the temperature has reached the desired level, diagnose the faults again.
Theory, where would we be without it?
First, a few words about when the fan should turn on and what is considered normal. The cooling system fan turns on automatically as soon as the coolant temperature reaches a certain point, usually in the range from 85° to 100°.
We recommend: What to do if the radiator leaks on the road?
When the engine is cold and it needs to quickly warm up the engine coolant through a small circle of the cooling system, bypassing the radiator, the electric fan is also turned off. As soon as the engine has warmed up to operating temperature, the thermostat is activated, which opens a large circle, that is, a circle with the participation of the radiator. This allows air flows to cool the antifreeze, preventing it from warming up above the permitted mark. But what to do if the air flow is not enough or the car has slowed down significantly or stopped altogether? The radiator cooling fan is specifically designed for these cases. It comes into operation when neither the large circle nor the air flow passing through the radiator honeycombs helps. The fan turns on automatically and forcibly cools the radiator, removing excess heat from it, thereby reducing the temperature of the coolant. If for some reason the fan suddenly does not work on a warm engine under load in the heat, this may mean that the coolant temperature will rise until cooling resumes. If the fan does not turn on, the engine temperature reaches a critical point, after which the engine boils, or rather the coolant boils, cooling is not carried out and the power unit works, which is called “peddling”. Even short-term overheating can have a detrimental effect on the condition of the motor and may result in an unpleasant breakdown in the future. Prolonged overheating usually ends with the antifreeze boiling away and the engine simply “jamming”, after which it becomes completely incapacitated.
Topical: Flushing the cooling system - how and why? Secrets and tips
Video about the reasons why the cooling fan on the VAZ-2114 does not turn on
As you know, fuel combustion occurs during operation of a car engine. This generates a large amount of heat as part of the conversion of thermal energy into mechanical energy. In this case, excess heat must be removed from the internal combustion engine to the external environment to prevent overheating of mechanisms and parts.
The engine itself should not overheat above the optimal 80-90°C. For this purpose, special devices are used, which together form a cooling system. Cooling systems are also divided into two types: liquid and air. In modern cars, these two types of systems are combined and are hybrid.
Although the liquid system is considered to be the main one, air cooling also deserves special attention, without which, under certain conditions, the car engine will inevitably overheat. Let's look at the air cooling system and its malfunctions in more detail.
Read in this article
Cooling fan malfunctions: symptoms and solutions
As mentioned above, an internal combustion engine is a complex system that requires uninterrupted operation of the cooling system. Otherwise, the power plant will overheat, which can lead to breakdown and, consequently, expensive repairs.
The liquid cooling system, through which special coolants (antifreeze/antifreeze) circulate, is closed. In a nutshell, the principle of operation of a liquid cooling system is that during engine operation, liquid circulates through its jacket (channels in the BC and cylinder head), which removes excess heat from heated parts.
The hot fluid then enters the radiator, cools, and returns to the engine to cool it. As the radiator passes, the heated coolant enters a network of thin tubes. This helps it cool quickly. Also, when the vehicle moves, the incoming air flow carries excess heat outside the engine compartment of the vehicle.
It is important to understand that only when these two systems interact does the engine effectively cool. Simply put, the fan thermal switch (fan sensor) trips and the fan turns on. As a result, an air flow is created and the fan runs until the optimum temperature is reached.
It consists of at least four blades, fastened together at a special angle for maximum air intake and delivery. The most popular was the 8-blade impeller. By design, the fan drive can be divided into 3 types:
- mechanical
- hydromechanical;
- electric;
Today, the first type is practically not used, especially on civilian vehicles, although it remains on powerful SUVs as the most reliable. The second type is also gradually fading into the background. In any case, if the device fails, immediate diagnosis and elimination of the cause of the failure is necessary.
Checking the cooling fan
So, when a modern fan breaks down, you need to take into account that they are often electric. As a rule, the problem lies in the wiring, sensors, fuses, etc. Among the main fan malfunctions, the most common cases are when the cooling fan:
- Doesn't turn on.
- They don't turn off.
- Turns on early.
- Air flow is not directed correctly.
By applying voltage to the fan itself, its serviceability is checked. If it spins, then the problem is not with it. If the fan does not spin, it is better to contact a car service. You can get to the service station on your own, adhering to certain rules:
- Drive at a speed of at least 60 km/h. Then the function of the broken fan will be performed by the incoming air.
- Turn the heater on to maximum while driving to release excess heat into the cabin. It will be hot in the cabin, but the chances that the engine will not overheat increase;
- Watch the engine temperature arrow on the panel. When it approaches the red zone, you need to stop the car, open the hood, and cool the engine.
avtoexperts.ru
When the engine is running, the temperature in the combustion chambers reaches about 1500-2000 degrees Celsius. If you do not remove heat from the cylinder walls, then overheating of the engine is inevitable and, as a result, expensive repairs or replacements.
Cooling Fan
To maintain the operating thermal conditions of the engine (+90 degrees) in any operating conditions, a cooling system is provided. It includes the following elements:
• Radiator; • Expansion tank; • Pump; • Thermostat; • Fan; • Temperature and fan sensors; • Set of connecting pipes; • Heater radiator; • Antifreeze.
Cooling system design
While the thermostat is closed, the working fluid circulates through the so-called small circle using a pump, cooling the cylinder block and the cylinder head, removing part of the thermal energy. When the thermostat opens, the liquid flow begins to move in a large circle, entering the cooling radiator.
Cooling system
While driving, the surface of the radiator is blown by a flow of oncoming air, reducing the temperature of the working fluid. However, the radiator itself is not able to prevent overheating of the liquid, for example, when the car is stuck in traffic jams or moving for a long time at low speed.
To assist the radiator, a fan is built into the cooling system of the power plant, being one of its main executive elements, and if it fails, a number of undesirable problems may arise.
How does a fan work?
On older generation machines, the fan worked forcefully, that is, it always worked while the engine was running, by means of a drive belt. Usually the fan itself was mounted on a pump pulley connected by a belt to the generator pulley.
Most modern cars use an electric fan or a drive with a viscous coupling (viscous coupling), where it is activated automatically by a switch on sensor (calibrated separately for each engine).
Radiator fan
The fan is a simple 12V electric motor, powered by the car's network. An impeller is installed on its shaft to create an air flow directed towards the radiator honeycombs. The fan itself has a mounting frame for connection to the radiator.
The activation sensor, in turn, is responsible for its operation, located in one of the radiator tanks. It is installed in the gap of the fan motor power supply wires.
Turning on the fan
Carburetor models
The fan switch sensor is programmed to a certain temperature limit at which its contacts are activated, sending power to the relay that closes the fan power circuit, and it starts working.
Injection engines
The fan on these machines is turned on via the control unit. The controller receives data from the sensor, then transmits it to the motor activation relay.
Possible causes of fan failure
In cases where the antifreeze temperature rose sharply and the fan on the radiator did not work, then, therefore, where the problem appeared. The car must be stopped and the malfunction repaired to prevent overheating and save the engine from costly repairs.
Malfunctions
• Fuse blown;
• Power sensor failure;
• Open circuit or short circuit in the electric motor power supply circuit;
• Electric motor malfunction;
• Poor contact in the connection or oxidation of contacts in the fan circuit;
• Turn-on relay failure;
• Malfunction of the safety valve in the expansion tank.
Examination
- the fuse blows due to some malfunction in the circuit it protects and before replacing it, it is necessary to find the reason for its operation;
— if the switching sensor fails, the power wires are connected to each other and if the fan works, then the sensor is faulty and requires replacement. To get to a service station or garage, you can leave the wires connected, while the fan will be constantly running, but the engine will be protected from overheating;
Scheme
On engines with an injector, the sensor is disconnected by removing the connector from it, the engine starts, and if the fan starts (the ECU will “understand” that there is a malfunction in the system and will turn on the fan in emergency mode), then the sensor is faulty and needs to be replaced.
— the power circuit is checked by a tester for integrity and absence of short circuit;
Checking with a tester
— if the fan motor fails, to check, the power supply is disconnected and power is supplied from the battery using two wires. If the fan does not start, it is therefore faulty (wear of the brushes, commutator, or problems with the armature and stator windings) and requires replacement;
— if there is a suspicion of unreliable contact in the fan connector, the chip is removed, the contacts are cleaned of dust and dirt and possible oxidation;
— a faulty relay can be temporarily replaced with a neighboring one if its parameters match;
Fan relay VAZ 2114
— when, even though the elements in the fan circuit are fully operational, it does not work when the temperature rises above normal, it is recommended to check the valve in the cap of the expansion tank.
The valve maintains pressure in the system above atmospheric pressure, preventing water contained in the working fluid from boiling when it reaches 100 degrees. If the valve is faulty, then the pressure equalizes atmospheric pressure and the liquid begins to boil at 100 degrees.
The sensor itself is triggered at a temperature of 105-107 degrees Celsius. It turns out that the liquid is already boiling, but the fan is not working yet. The valve cover needs to be replaced.
Some tips
• Periodically monitor the coolant temperature and check the operation of the fan when entering the danger zone on the device indicator;
• Check the fluid level in the reservoir and replenish if necessary;
• Monitor the system for possible fluid leaks;
• If the operating temperature is exceeded, stop, find and eliminate the cause;
• Seasonally, make it a habit to wash the expansion tank cap under water pressure, which will help keep the safety valve clean;
• On motors where the fan operates forcibly, periodically check the tension of its drive belt.
What's the result?
Having examined the operating features of the radiator fan, it becomes obvious that the internal combustion engine cooling system as a whole and the engine cooling fan itself make it possible to maintain the required temperature regime of the internal combustion engine.
It is also important to understand that the uninterrupted operation of the cooling system depends on the coordinated operation of all components. For example, the fan normally turns on when the engine temperature rises above 90°C to cool the engine, and then should turn off.
However, in practice, you can often independently diagnose a problematic device, identify the cause of the breakdown and, if possible, fix the problem. Finally, we note that most problems associated with engine overheating can be avoided through preventative checks, as well as regular cleaning of the cooling fan terminals and contacts.
There is air in the engine cooling system: symptoms of airing, reasons for the formation of an air lock. How to bleed the engine cooling system.
The engine cooling fan turns on when the engine is cold or after the ignition is turned on: the main causes and solutions to the problem.
Design and principle of operation of a radiator cooling fan. Common faults, troubleshooting and repairs. Tips for use.
Common engine cooling system failures: water pump, thermostat, radiator, cooling fan and others. How to determine the reasons yourself.
Why does the engine overheat or boil while the cooling radiator is cold? Signs of engine overheating, how to prevent serious consequences.
Radiator in the cooling system, design and principle of operation, thermoregulation of the coolant. Troubleshooting and self-repair
Radiator fan runs constantly
This case is partially discussed above; the cause is a failure of the temperature sensor or a short circuit in the wires going to the fan. But if it is constantly spinning, then this may be caused by a stuck relay. This happens quite often, especially after the relay is triggered and the fan should turn on. Sticking relay contacts mean that they cannot open, which causes a constant voltage supply to the contacts, causing the electric motor to spin constantly. The consequences of sticking relay contacts include the fact that the radiator fan does not turn off.
Often the thermostat may be the reason why the fan shutoff does not work . The fact is that the sensor is located in the head of the unit; it determines when the fan should turn on. But the coolant can move in a large and small circle; when it moves in a small circle, it does not enter the radiator for cooling. The mode of water movement is determined by the thermostat.
If it is jammed in the position of water moving in a small circle, then it will continue to move and overheat, which will trigger the sensor and turn on the fan, but because... water does not enter the radiator, it will not cool, and the sensor will constantly signal a high temperature. As a result, the radiator fan does not turn off. This case can be determined simply - you need to touch the hoses going to the radiator. When the thermostat is stuck, they will be cold if the engine is overheated.
If the radiator fan does not turn off due to a jammed thermostat, then sometimes you can knock on the case to eliminate this phenomenon. Often this is enough and the defect disappears. If everything remains unchanged, then you will have to remove the thermostat, take out all the stuffing from it and then put the device itself back in place. Another option for the same defect would be the thermostat getting stuck in an intermediate position. This can also result in the radiator fan not turning off, but this situation is much more difficult to diagnose. Such difficulties are caused by the fact that a certain amount of water enters the radiator, but too little of it passes through, all the water does not have time to cool, which leads to overheating of the engine.
All of the above is not a complete description of the possible reasons why the radiator fan does not turn off. There can be many of them, sometimes quite strange and unexpected, but in each of these manifestations of malfunctions it is necessary to look for the reasons and conduct a thorough analysis.
