Causes of not working radiator fan. The principle of operation of the radiator fan and the main malfunctions

28.09.2019

The main task of the cooling fan is to reduce the temperature of the engine and radiator that rises when the engine is running. In fact, it directs hot air outside, replacing it with cool "outside" air, and thereby lowering the temperature of the engine, radiator and coolant (coolant).

It should be noted that the fan is one of two important elements of the cooling system (by the way, it is considered hybrid in VAZ cars). The second element is the liquid cooling system.

There are two types of fans - mechanical (attached with a belt to a pulley / crankshaft) and electrically driven. The latter consists of two equivalent parts - an electric motor and a control system (including a coolant temperature sensor and a fan switch relay). As a rule, VAZ users deal with electric fans.

Problems with the radiator cooling fan can occur in any car whose age is significant enough to manifest itself as "senile ailments". These problems, depending on the situation, can manifest themselves in unstable operation of the fan, its belated start, or a complete failure. In the latter case, the cooling fan simply does not turn on - and this is the most common problem.

VAZ cooling fan does not turn on

Since this problem is the most common, then it needs to be given the most attention. And first of all, it should be noted that this problem can be caused by a significant number of reasons, and therefore the most costly (at least in terms of time) stage will be diagnostics.

The reason why the 2110 cooling fan does not turn on, as well as almost any other AvtoVAZ model, may be, for example, due to a blown fuse. This is the most common cause of fan failure, and the easiest in terms of fixing the problem. For the same reason, the cooling fan for the VAZ 2115 and other, later models of VAZ cars often does not turn on. To eliminate this malfunction, it is enough to replace the faulty fuse with a working one - and the problem is eliminated. You can replace both one fuse (if you have already figured out the circuit or you have time for this), and the fuse box in a complex. If the car is many years old, the second option is preferable.

Another reason why the Kalina or Priora cooling fan does not turn on may be a malfunction of any element of the electrical network of your car. In this case, at least for inexperienced craftsmen, it will be much easier and faster to turn to professionals for help, since even diagnostics will require a lot of effort - and the use of special diagnostic equipment (for "ringing" electrical wiring).

In addition, if the cooling fan does not turn on, the reasons can also be found in the thermostat - if the latter is faulty, then the system may simply not respond to the need to connect the cooling system. A failed or stuck thermostat blocks the circulation of coolant in the system (including through the radiator), the radiator sensor does not detect elevated coolant temperatures, the fan does not turn on - and the engine “boils” after a few minutes of operation. It is recommended to check the thermostat first of all if you find a fan failure.

The user manuals state that the 2107 cooling fan does not turn on, often due to faulty wiring. Indeed, this reason can take place, but it is not among the top three in terms of frequency. As a rule, problems arise in situations where the wiring of the fan has not been changed for many years. Rotting wiring is not just a reason for fan failure, but also a possible cause of much more serious malfunctions and even fires, so control in this area is absolutely necessary.

In many sources, you can find information that the cooling fan 2114 does not turn on, for example, for a banal reason - the fan itself is faulty. This happens relatively rarely, but it can be the cause of the problem. Both the fan itself and the plug can fail (the latter is more common, and rather refers to the previous paragraph).

The fan switch sensor (it is located on the radiator) may also be faulty - and this leads to blocking the fan. Identification of a faulty unit is carried out by a sequential check of the operability of individual elements of the system. Excluding this or that element, we connect the wiring directly: if we see a spark or signs of life the fan itself gives, then the excluded element is the “weak link”.

Another reason why the cooling fan 2109, 2107, 2114 and other VAZ models does not turn on. It's a blown head gasket. In this case, the movement of the coolant is prevented by an air lock, which can be easily diagnosed by the bubbles that appear from the expansion tank while the engine is running. By replacing the gasket, you can easily solve this problem. However, it is important to pay attention to the condition of the cylinder - with such a problem (especially if it appeared some time ago), cracks may well be found in the cylinder.

The cooling fan turns on too often

This problem occurs relatively rarely, and here it is necessary to understand very clearly where there is a norm, and where the system should already be diagnosed. Novice motorists, having read in the user manual that the fan is “supposed” to turn on only at a temperature of 105 degrees, are worried that the cooling system is turned on at a lower temperature.

In fact, things are somewhat different. The temperature of 85-95 degrees should be considered the norm, the cooling system should work higher, otherwise, there is a high risk of engine “boiling”. However, much depends on the driving conditions - one thing on the highway, and another - in the city, and especially when driving in a traffic jam. If in traffic jams the fan turns on every one and a half minutes, this indicates that the system is working well, because the engine at 10-15 kilometers per hour, and even in the “drive-stop” mode, works at increased loads. Accordingly, turning on the fan indicates its serviceability.

Just in case, it is better to check the thermostat for operability, the integrity of the cylinder head gasket.

In addition, you can check the coolant flow - if the coolant "leaves" too quickly (for example, less than a month passes from full load to a minimum), it is necessary to check for leaks as soon as possible. And, most likely, those will be found.

A decrease in the efficiency of the cooling system can also occur due to banal blockages (deposits) and technical side effects (air lock). In the first case, it is recommended to flush the radiator with a regular cleaning agent. As for the air congestion, you can either try to “squeeze out” it at high speed, but this is fraught with problems with the traffic police, and in a particularly neglected case, a fatal accident. Much more productive will be the usual "pumping" in the garage. Moreover, there are a lot of instructions for eliminating the air lock.

Good luck on the road to you and your VAZ!

The internal combustion engine installed on the machine operates in difficult high-temperature conditions. The increase in temperature is caused by the placement of combustion chambers in the cylinders of the block and the distribution of the generated heat to all parts of the engine, as well as from the friction of the pistons in the cylinders and various bearings (rolling and sliding) when reciprocating and rotating parts.

Why is the radiator fan not working?

An uncontrolled increase in temperature leads to the destruction of rubbing parts and complete engine jamming. To avoid such troubles, the engine has a cooling system, the purpose of which follows from its name.

On internal combustion engines, the following types of cooling can be used: air(open type); liquid(closed type); combined(air-liquid). The purpose and operation of fans of all types of cooling are approximately the same. They differ in rotation drive and operation control. According to the baits of rotation, they distinguish: mechanical, electrical, electromagnetic and hydraulic drives for fan rotation.

Mechanical drives for fan rotation include V-belt drives and gear drives. The disadvantages of these drives include: their constant operation (with the engine running), and, accordingly, power take-off and excessive fuel consumption; low efficiency of temperature control due to the inability to regulate the fan speed or ensure its shutdown; a large load on the coolant pump, leading to its rapid failure.

Hydraulic, electric and electromagnetic drives are devoid of the disadvantages listed above. These drives are controlled automatically, maintain the specified temperature regime of the engine, reduce dynamic loads on the blades, and reduce noise when the vehicle is moving. TO disadvantage These drives include: design complexity, high cost of units and repairs in general.

There can be many failures in the operation of mechanically driven fans. Let's take a look at the more typical ones:

- the tension of the belt (belts) of the fan drive has weakened due to poor-quality adjustment or belt stretching;

Belt slip due to lubricants getting on it;

Weakening of the belt (belts) due to the loosening of the nuts securing the generator or tension roller;

Jamming of the coolant pump shaft bearing (bearing failure due to lack of lubrication, increased static load on the bearing due to overtensioning of the fan drive belt ...);

Bundle drive belt;

Broken drive belt.

WARNING! If a fan with an electric drive does not come into operation, then during diagnostics, first of all, it is necessary to exclude mechanical damage to the fan and the destruction of the fan shaft bearing.

When checking the electrical part of the fan drive, it is necessary to verify the integrity of the fan fuses, check the integrity and appropriate length of the motor brushes, and also verify the integrity of the electrical wiring; check the health of the collector and motor windings. A malfunction may occur due to a malfunction of the temperature sensor, relay, or loose contacts in the connectors, as well as. Another reason for the fan not turning on may be a thermostat failure. The reasons for the failure of hydraulically driven fans can be the same as those with a mechanical drive, plus the failure of the fluid coupling.

How to check the radiator fan yourself.

Checking the mechanically driven radiator cooling fan is not very difficult. During the operation of the car, it is necessary to monitor the coolant temperature gauge, preventing it from overheating (especially boiling). In order to make sure that the fan is working reliably, it is necessary to make a visual inspection and make sure that the belts are intact (no breakage, delamination), no oiling of the belts.

Check the tension of the fan drive belts, and if it is loose, make sure that the generator (tension roller) is securely fastened, that the belts are not stretched. Check the absence of jamming when the fan rotates (check with the belts removed), its jamming, the absence of play in the coolant pump bearings.

Checking the performance of an electrically driven fan requires basic knowledge of working with electricity. The check must begin with an analysis of the readings of the coolant temperature gauge. If an increase in temperature is detected, its cause must be determined. WARNING! Disconnect the battery negative terminal before diagnosing electrically driven fans.

After making sure that there are malfunctions in the operation of the fan, proceed to troubleshooting. First of all, check the operation of the mechanical part, that is, the absence of visible damage, make sure that the fan rotates freely, without jamming, and also check the operation of the thermostat. After that, proceed to check the electrical part . First of all, it is necessary to check the integrity of the fuses. If the fuse(s) are blown, look for where the short circuit occurred. If all the fuses are intact, we check the operability of the fan motor (fans).

The operation of the electric motor can be checked by emergency turning on the fan, for this it is necessary to disconnect the terminals from the temperature sensor and start the engine - the fan should work. A more reliable check of the electric motor can be made by connecting the battery directly to the engine. If the electric motor does not work, check the serviceability of the electric brushes, the integrity of the winding, the health of the collector. If the motor is running, check the fan switch relay is working.

To do this, you need to remove the block from the fan switch relay. Having activated the emergency switching on of the fans, we pull out the relay one by one from the socket, by turning off the fans we determine their performance. We check the serviceability of the negative and positive wires, their integrity, the absence of insulation melting, the exposure of the wires, the reliability of the contacts in the connectors.

Check for a negative coming from the ECU to the fan relay. If faulty parts are identified, they are replaced, as well as further checking the health of the electrical wiring in order to prevent repeated failure of the fans.

What you need to check the radiator fan.

No special equipment is required to test a mechanically driven radiator fan. The integrity and serviceability of the fan drive, as well as itself, is determined by a careful inspection using the tool that the machine is equipped with. Suitable spare parts are required for repairs.

To check the fan with an electric drive, in addition to a car tool, you must have an indicator (to check the health of the electrical wiring), a tester (to check the health of the electrical wiring, as well as measuring the voltage and resistance of parts). This work does not require high qualifications, but it takes a lot of time to detect a malfunction (the less experience, the more time is required), as well as strict adherence to safety measures.

No automotive system will work properly if the temperature is not optimal. This is especially true of the motor, which is very active, which is why it gets very hot. In order for the unit not to overheat, a special cooling system is included in its design, which is responsible for heat removal. The system has such a device as a radiator through which the coolant moves.

Together with the car, a fan is also installed, which drives air. Naturally, the fan can fail from time to time. What are the typical malfunctions of this fan? How to fix them? Let's look into all this.

Frequent malfunctions of the radiator fan

If the cooling fan breaks down, sooner or later the power unit will overheat. That is why you need to carefully monitor the condition of the fan, or rather, its performance. If the fan is broken, then it is necessary to determine the cause of the breakdown and fix it as soon as possible. Most often, the car radiator fan either does not work at all, or works constantly. Let us specify the manifestations of these problems.

In the first case, the fan may either not turn on at all, or simply not turn off. Despite the fact that there are only two problems, there are several reasons for their occurrence. You can check for yourself how the fan works. To do this, you just need to start the engine without moving.

Wait a while until the coolant has warmed up to a temperature above the optimum. When the temperature is sufficient, that is, it goes beyond the red limit of the corresponding sensor, then the fan should turn on, which will cause additional noise under the hood. But if the temperature arrow has already gone beyond the red mark, and the fan has not turned on, then immediately stop the motor, wait until it cools down, and then proceed to search for the causes of the breakdown.

First, inspect the fan motor. To check, connect it directly to the battery if the engine is carbureted. In cases with injection engines, the connector must be removed from the sensor, after which the fan should work, and in emergency mode. If after connecting the fan does not turn on, you will have to buy a new one. But if it works, then everything is fine with it, and it is not necessary to check it, but, for example, a temperature sensor. Often, it is mounted in a radiator.

Turn it off by disconnecting the wires, and short them together. If the fan turns on at this point, the sensor is broken and must be replaced. Check fan power wires for breaks. Be sure to inspect the fuse and relay that is responsible for supplying power to the fan. The fuse is responsible for sound signals, so to check its performance, just press the horn. The relay must be checked for sticking contacts. You should also check the performance of the device with the voltage going to it. If the reaction is zero, then the relay needs to be changed. If you carefully inspect everything, you will surely determine what the problem is.

Now let's deal with the constant operation of the fan. One possible reason for the constant operation of the cooling fan may be the sticking of the relay contacts in the position in which the electric motor is energized. Another such situation is possible when the thermostat is jammed in the position that corresponds to the movement of the liquid in a small circle. But this is only possible if the machine does not have a separate temperature sensor that is responsible for driving the fan.

Then the liquid overheats, the fan turns on, but the coolant does not enter the radiator. The fluid temperature will remain high although the fan will run. The thermostat can also jam in an intermediate position, that is, the liquid will go to the radiator, but due to the partial opening, it will not completely get into the radiator, that is, it will not cool completely. Nevertheless, if the fan is constantly running, then it is not as bad as its non-functioning. Therefore, you need to know exactly what to do if a breakdown of the unit is detected.

How to Troubleshoot a Radiator Fan

Before removing the fan, disconnect the ground terminal from the car battery along with all wires that go to the fan. Only then can the fan be removed. So that the breakdown does not recur, and the cooling process proceeds more efficiently, experts recommend cleaning the fan from time to time, removing various kinds of pollution. A brush must be used for cleaning.

It happens that the fan breaks due to ordinary dirt. To check if this is the case, fold back the engine cover and evaluate the condition of the equipment. As practice shows, you will have to buy new brushes, because they most often break due to too much dirt and premature wear.

Quite often, the fan breaks down due to bad contacts. This phenomenon is typical for oxidized contacts if you have never cleaned them. Therefore, before checking the fan, check the wires, if necessary, replace them.

The next step is to check the performance of the rotor, its winding. If an open or short is detected, each turn will need to be inspected in order to determine the breakdown. Clean the winding in advance with a metal brush and a rag soaked in solvent. It is forbidden to use products that contain aggressive elements.

If you have determined that the electric motor is broken, then you will have to buy a new device. If you are on the road, the engine temperature has become critical, and the radiator has not turned on, then first you need to stop the car, and then wait until the engine cools down. Next, you can try the following:

1) Pick up speed more than 60 km / h, so the liquid will be cooled by oncoming air flows;

2) Short the wires that go to the sensor to force the fan on;

3) Turn on the car's interior heating system at full power, so some of the heat from the liquid will go to the passenger compartment.

Other radiator malfunctions

It happens that the radiator fan turns on ahead of time. The temperature sensor is the culprit. Often, it incorrectly determines the temperature, which is why it sends a signal to the fan at the wrong time.

In this matter, you need to choose the right sensor. They are of two types - summer And winter and they have different temperatures. For example, a winter sensor will work later, and a summer one earlier. If you choose the wrong device, then do not be surprised that the fan in your car will turn on either earlier or later than necessary. The sensor may work correctly, but the temperature range is not suitable for the device.

Many car enthusiasts underestimate how important and useful a car radiator fan is. If you do not pay attention to the breakdown, you risk paying a decent amount for the repair of an overheated engine. That is why it is necessary to diagnose the fan problem in time and fix it as soon as possible.

Cooling fan problems tend to occur on used cars with decent mileage. This failure manifests itself in different ways, the fan may not work stably, it may turn on late or not turn on at all. Today we will talk about the last malfunction, that is, the situation when the cooling fan does not turn on at a certain moment. You will learn why this happens, where to look for the cause, and in what order. Let's take "" as an example, but the method itself and the reasons will be almost the same for all VAZ models.

The search for a breakdown is not so much laborious as comprehensive, because there can be quite a few reasons why the fan does not turn on, from a banal blown fuse to more complex problems associated with a malfunctioning thermostat or problems with the electrical wiring of the car's on-board network.

If the engine starts to boil, but the fan does not turn on, then the first thing that comes to mind for most motorists is problems with the fan wiring. However, very often the wiring has nothing to do with it, and the real reason lies precisely in the thermostat. A device designed to control the temperature of the coolant (coolant) may fail or simply jam, after which the coolant stops circulating through the radiator, as a result, the radiator sensor does not work, and the fan itself does not turn on. How to check the thermostat read.

The next contender for verification is the fuse that is responsible for the fan, if you replace it with a whole one.

If the cause is not the fuse, you need to check the fan itself directly. Power wires are suitable for it, often from old age they simply crumble or break off. Alternatively, the reason may lie in the plug, so if everything is “good” with the wiring, turn off the power to the fan and check the plug for a malfunction. Connect the power to the fan directly, for example, from the battery, if the fan does not react in any way, we conclude that the fan is faulty.

(DVV) located on the radiator. To do this, disconnect the plugs, and then connect them together if the fan does not work and needs to be replaced.

It is necessary to connect the wire going to the fuse box directly to ground (usually white with a black stripe). If after that the fan starts working, we can conclude that the second black wire has broken, try to find a break and check whether its connection to ground is reliable. After that, we connect the two wires together, and see what happens if the fan turns on, then the problem was a bad connection.

Check the fan relay, it is possible that the problem is in it. In order to find out, simply replace it with an adjacent relay, then connect the wires of the radiator sensor to each other, see above. The fan will turn on - the problem is a faulty relay.

Next, you need to check the voltage, whether it is supplied to the fan through the fuse box. To do this, we take a piece of wire and install it in the relay connectors, if the fan is running, the reason why the fan does not work is in the fuse box.

It is likely that voltage is not being supplied to the fan relay. To check this, you can use the "grandfather" method. We take a light bulb, which will serve as a "control". If there is no light bulb, just lightly strike the second end of the wire by mass, if you see a spark, there should be no problems, most likely this is not the reason. If you don’t see a spark, most likely there is no voltage in this connector, that is, there is a break in the track in the fuse box.

If, when checking all of the above, you find the reason why the radiator fan does not turn on, it remains to check one wire - the wire of the radiator sensor. To do this, you must remove the switch, as it does not allow you to get close to the fuse box plugs. So, we remove the plug chip from the fuse box, and check the wire of the radiator sensor for a break.

We check as follows: connect the wire to the "+" terminal, install the other end into the chip connector. Next, remove the plug from the sensor and connect the bulb. If there is no light bulb, we make a “teal” to ground. If there is no voltage, most likely this wire is broken.

If the fan does not turn on, then the reason may be completely unexpected, for example -. The inclusion does not occur for the reason that it does not enter the cylinder, while the gases from the cylinder penetrate into the coolant, creating an effect known as. This plug is preventing the coolant from flowing normally. How to understand that you have a burnout? It is enough to look into the expansion tank, if bubbles come out of it every now and then - you have a burnt gasket, or there is a crack in the cylinder.

In the production of cheap models, the manufacturer saves on the quality of materials, so they break more often than more expensive counterparts. If the fan stops working, then do not rush to throw it away, because in most cases it will not take much time and financial costs to restore its performance.

I won't dwell on mechanical failures such as repair of the impeller, housing, turning mechanism, etc. To eliminate these breakdowns, it is simply necessary to restore the worn or broken part or replace it with a new one. This article will address the issues of repairing the electrical part of the fan, in which the electric motor does not turn on or works with a hum, unpleasant smells of burning or jamming. A more complex floor model will be taken for consideration. Built-in exhaust fans are structurally much simpler, due to the lack of a speed switch unit, so they are even easier to repair. But repair, given the price of a simple model of an exhaust fan without bells and whistles, is impractical.

For that to find the reason fan failure, it will need to be disassembled. Doing it yourself will be quite simple and fast. First remove the protective grill, then the blades or the fan impeller, which is fixed with a nut. Next, you need to remove the second part of the protective grille and unscrew the cover screws.

Troubleshooting when repairing a domestic fan

Before starting repairs with your own hands, you need to study the schematic diagram of the operation of the device.

As a rule, an asynchronous electric motor is installed in a floor fan, consisting of eight windings (working and starting). A 90 degree phase shift is required for a successful launch. For these purposes, a capacitor is installed. The device starts working after pressing the power button, after which the indicator lamp lights up and the motor starts, the rotation speed of which depends on the winding switching circuit, for which the 3-speed switch is responsible with mechanical blocking of the simultaneous activation of several buttons, which may cause short circuits.

Before starting to check the electric motor:

Straightaway you need to check the cord connection to an electrical outlet. To do this, you must first disassemble the switch block, and then, in compliance with electrical safety measures, check with a multimeter for the presence of 220 volts at the light bulb contacts.
Check the condition of the capacitor By .
Ring for integrity and check the reliability of all wire contacts and connections in the circuit.
If a hum is heard when the fan is running or noise, then lubricate the plastic parts inside the gearbox with Litol or Solidol through the holes that are specially provided for this in it.
Check for 220 volts at the output with the included switch button.

Fan Motor Repair

Do-it-yourself electric motor repair must begin with lubrication of the bearings, very often after that the fan starts to work normally. The motor shaft rotates in plastic bushings. Machine oil is suitable for lubrication - drop a couple of drops of oil in bulk at an angle so that it flows into the inside of the bushing, and then rotate the shaft back and forth along the axis until it starts to rotate easily.

Probability of rotor failure motor is relatively small and in my practice of repairing household appliances has not yet been encountered, because EMF is induced in the rotor (current occurs) under the influence of the stator windings.

Often in electric motors household fans, an open occurs in one of the stator windings. If at least one winding is broken, then the engine will not work at all. To check, it is enough to sharply spin the blades clockwise. Just immediately remove your hand sharply from the blades so as not to get injured. If after that the floor fan starts to work, then one of the windings has burned out. Please note that if the winding connected from the capacitor is broken, the fan will not work in any case. To determine the integrity of all windings, I recommend ringing them with a multimeter using. Please note that the winding resistance should not be too high or zero.

Very important before disconnecting the wires from the windings, do not mix them up when connecting, therefore, before removing the wires, mark them differently if they are of the same color. Before removing wires or starting to disassemble any devices with my own hands, I always take photos of all stages. If there are then questions or doubts during assembly, then the photos help out a lot.

If the stator winding is broken or burned out, given the price of a floor or built-in fan, I do not recommend rewinding or repairing the winding. In this case, it is better to buy a new model.

The service life of the fan motor is reduced several times, if you do not periodically clean it from dust and dirt, as well as if you do not lubricate the bearings or gearbox during the time.