DIY cooling fan repair

In detail: do-it-yourself cooling fan repair from a real master for the site my.housecope.com.

What to do if the radiator fan is not working?
Frequent malfunctions of the radiator fan
How to troubleshoot a radiator fan
Other radiator malfunctions

No car system will work properly if the temperature is not optimal. This is especially true of the motor, which works very actively, which is why it gets very hot. To ensure that the unit does not overheat, a special cooling system is included in its design, which is responsible for removing heat. The system has such a device as a radiator through which the coolant moves.

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

If the cooling fan breaks down, sooner or later the power unit will overheat. That is why you need to closely 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 runs constantly. Let us concretize 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 efficient the fan is. To do this, you just need to start the engine without moving.

Wait a little until the coolant has warmed up to a temperature above optimum. When the temperature is sufficient, that is, it goes beyond the red line 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 start looking 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, then you will have to buy a new one. But if it works, then everything is fine with it, and you need to check not it, but, for example, a temperature sensor. Often, it is mounted in a radiator.

Video (click to play).

Disconnect it by disconnecting the wires and short-circuit it together. If at this moment the fan turns on, then the sensor is broken and must be replaced. Check the fan power wires for breaks. Be sure to inspect the fuse and relay that supplies power to the fan. The fuse is responsible for sound signals, therefore, to check its performance, it is enough to press the horn. The relay must be checked for sticking contacts. You should also check the performance of the device when the voltage goes to it. If the reaction is zero, then the relay needs to be changed. If you examine everything carefully, you will surely determine what the problem is.

Now let's figure out the constant operation of the fan.One of the possible reasons 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. Such a situation is also possible when the thermostat is jammed in the position that corresponds to the movement of the liquid in a small circle. But this is possible only if the car does not have a separate temperature sensor, which 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 while the fan is running. The thermostat can also jam in an intermediate position, that is, the liquid will go to the radiator, but due to partial opening, it will not completely enter the radiator, that is, it will not cool completely. Still, if the fan runs constantly, then this is not as bad as its non-functioning. Therefore, you need to know exactly what to do if a unit breakdown is detected.

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 dismantled. So that the breakdown does not recur, and the cooling process proceeds more efficiently, experts recommend from time to time to clean the fan, removing various kinds of contamination. You need to use a brush for cleaning.

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

Quite often, the fan breaks down due to poor 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 and its winding. If an open or short circuit is detected, it will be necessary to inspect each loop in order to determine the breakdown. Clean the winding well in advance with a metal brush and a cloth soaked in solvent. It is forbidden to use products that contain aggressive elements.

If you determine that the fan motor is broken, 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 for the engine to cool down. Then you can try the following:

1) Accelerate more than 60 km / h, so the liquid will be cooled by oncoming air currents;

2) Short-circuit the wires that go to the sensor to forcibly turn on the fan;

3) Turn on the heating system of the passenger compartment at full power, so part of the heat from the liquid will go to the passenger compartment.

It so happens that the radiator fan turns on ahead of time. The temperature sensor is to blame for this. Often, it incorrectly determines the temperature, which is why it does not send a signal to the fan at the right time.

In this matter, you need to choose the right sensor. They are of two types - summer and winter, and their temperature regime is different. For example, the winter sensor will be triggered later, and the 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 ignore the breakdown, you risk paying a decent amount for repairing an overheated engine.That is why you need to diagnose the fan problem in time and fix it as soon as possible.

The engine cooling fan is a special device that blows the radiator and the heated car engine by constantly and evenly removing excess heat into the atmosphere.

The design of this mechanism, which is often called a radiator fan, is quite simple. It provides for the presence of one pulley, on which four or more blades are located. In relation to the plane of rotation, they are mounted at a certain angle, due to which the intensity of air injection increases (below we will tell you exactly where the fan is blowing).

There is also a drive in the design. It can be: hydromechanical; mechanical; electric. The hydromechanical type drive is a hydraulic or special viscous coupling. The latter receives the required movement from the crankshaft. Such a sleeve is partially or completely blocked when the temperature of the silicone composition filling it rises.

The temperature rise itself is caused by an increase in the load on the vehicle engine, which occurs when the number of crankshaft revolutions increases. The fan turns on when the clutch is blocked. But the block of the hydraulic clutch turns on when the volume of oil changes in it. This is its fundamental difference from the viscous adaptation.

Mechanical drive is understood as a drive carried out by a belt drive from the engine crankshaft. On modern cars, it is practically not used, since significant power of the internal combustion engine is expended to rotate the fan (the engine gives too much of its energy). But the electric drive, on the contrary, is used very often. It consists of two main components - the control system and the fan motor for the engine cooling system.

The control system monitors the temperature of the car's engine and ensures the functioning of the cooling mechanism. The drive electric motor is connected to the on-board computer. The control circuit of a standard electric actuator consists of:

ECU (electronic control unit);
a temperature sensor that monitors the temperature of the cooling composition;
air flow meter;
a relay (in fact, a regulator), at whose command the fan turns on and off;
sensor for counting the crankshaft revolutions.

In this case, the actuator is precisely the electric motor that provides the drive. The principle of operation of the sounded circuit is quite simple: the sensors transmit messages to the ECU; the electronic unit, where the signals go, processes them; after analyzing the messages, the ECU starts the fan controller (relay).

Many cars of the last years of production in their design do not have a regulator, according to the commands of which the fan turns on and off, but a separate control unit. Its use guarantees a more economical and truly efficient operation of the entire cooling system (the unit always knows where the fan is blowing, at what angle it is located, when it is necessary to turn off the device, and so on).

Neither the most innovative electric motor with high power, nor the ultra-reliable unit or control regulator is able to one hundred percent protect the cooling system from damage. Considering that a failed cooling fan, which blows in the wrong place, or does not rotate at all, can become the culprit for engine overheating, it is required to constantly monitor its normal functioning.

A timely repair of the system components will save your car from many troubles, but here it is important to correctly establish the cause of the fan breakdown. In other words, first you need to find a problem for which, for example, the crankshaft speed controller or the control unit or the electric motor does not work.Any driver can diagnose fan malfunctions based on the following recommendations.

The check should begin with dismantling the connector (plug) of the temperature sensor and examining it. In cases where the sensor is single, you need to take a small piece of ordinary wire and short-circuit it in the terminal plug. With a working fan, the control unit or relay must give a command to turn it on when it is closed. If the device of interest to us does not turn on during such a check, this means that it needs to be repaired or replaced.

In the presence of a double temperature sensor, the verification principle changes slightly, and is performed in two stages:

The red and red and white wires are closed. In this case, the slow rotation of the fan should be recorded.
Red and black wiring closes. The rotation should now speed up significantly.

If there is no rotation, the fan will have to be dismantled and a new device installed in its place. If the radiator cooling fan is constantly running (blowing without interruption), there is a possibility that the sensor for its activation is out of order. It is not difficult to verify such a suspicion. It is necessary to turn on the ignition, and then remove the tip of the wire from the sensor.

If the device did not turn off after that, you can safely buy a new regulator (sensor) for turning off the device. Situations where the radiator cooling fan is constantly running are not uncommon, and now you know how to solve this problem. It also makes sense to check the fuse in cases where you doubt the functionality of the mechanism described in the article. This is done like this:

from the positive terminal of the battery, power is supplied to the red-black or red-white wiring in the fan connector;
from the negative terminal, charge is applied to the brown wires.

If the regulator or the unit did not respond (the device did not turn on), check the temperature sensor wire (all connectors and plugs on it). It may be necessary to make simple repairs to the cable (for example, insulating it, replacing the plug). If it's not about the wire, then you will have to purchase a new fan, since yours is broken.

A decent level of cooling of the radiator and engine of the machine is achieved only when the fan is periodically checked for various minor breakdowns and contamination. It is not difficult to carry out such a check regularly and use a brush to clean the device from dirt and dust.The principle of dismantling the fan is simple: the ground wire is thrown from the battery; disconnect all, without exception, the wires that fit the node in question; unscrew the mounting bolts of the device. Now you can slightly move the fan shroud and look at its condition. Such an inspection allows you to identify a lot of breakdowns and perform: Image - DIY cooling fan repair

Stripping and replacing wires: their poor-quality contact is often the reason for inadequate operation of the fan.
Repair of brushes (or rather their replacement): this element of the system fails more often than others, since the brushes wear out very quickly, collecting all the dirt from the road.
Elimination of short circuit or breakage of the rotor windings: sometimes they are in working order, but they do not function well due to the accumulated dirt on them. It is not at all difficult to solve this problem - it is enough to soak a rag in solvents and scrupulously clean the windings (if necessary, it is allowed to use special brushes for cleaning).

Sometimes it is necessary to change the electric motor (for example, when the fan does not start when the engine is well warmed up). Unfortunately, this important part of the cooling device is not repaired.

In this article, we cannot ignore the question of where the mechanism of interest to us blows. It is this question that is asked to experts and fellow motorists by users in dozens and hundreds of forums dedicated to vehicle maintenance.In fact, the answer is very simple. Image - DIY cooling fan repair

The very purpose of the cooling device and the principle of its operation, described above, tells us that it blows exclusively on the engine, sucking in cold air through the radiator.

If in your car the air flow is directed not at the motor, but at the radiator, this only means that the fan was incorrectly connected after maintenance or repair work. Most likely, the terminals were simply confused. You should install them correctly, and never again wonder where the fan should direct the flow of cooled air.

If a household fan breaks down, both desktop and floor-standing, do not rush to immediately take it for repairs, let alone throw it away. Most likely, there is a simple problem, and you can repair the fan yourself.The household fan does not differ in design complexity, and the principle of its device can be seen in the figure below.If you look closely at the drawing, it becomes clear that an electric motor, a gearbox, a crank, a rotation speed switch and a propeller that creates an air flow can fail in the apparatus. The main difference between a desktop cooler and a floor-standing cooler is a high stand in the floor-standing version. The rest of the designs are identical.So, the main malfunctions that you can observe with the cooler you purchased:

the unit does not turn on, the power lamp is off;

the device does not work, but the light is on;

cooler blades do not rotate well;

the unit does not turn to the sides;

cooler hums and does not rotate.

In this situation, there can be 2 options: the lamp indicating the readiness of the unit for operation can light up or not. Depending on this, the breakdown diagnostic algorithm will differ.If, after turning on the device, the light located on its body does not light up and it does not start, then, first of all, you need to check if there is outlet voltage... This is done simply: take any electrical appliance and plug it into this outlet. If the device works, then you need to look for a malfunction in the electrical plug and cord.To check the plug, unscrew it and check the reliability of the wire connection to the terminals. To check the cable, you need to disconnect it from the terminal block of the device and "ring" the tester. If a break is found in the cable veins, it should be replaced.The reason for this behavior of the unit, when the indicator light is on, but the fan does not work, and no sounds are heard, may be caused by breakdown of the block with buttons... To test the buttons, you need to disassemble the button block located on the floor fan stand or stand near the tabletop apparatus. But, before disassembling the device, make sure that it is unplugged from the outlet.The operation of the buttons is very simple: there is an “on” and “off” position. It is necessary with the help of a tester to check the “output” and “input” on each key.If a faulty button is found, it will not be possible to repair it. Therefore, the switch should be replaced or a direct connection made. This approach to solving the problem will help to start the unit into operation if you are far from the store, for example, in the country.Defective speed switches can also be the reason why the fan does not turn on. To test the regulator, you will need to put it in the maximum position and check the “input” and “output” using the same tester.In the case when the fan does not pull and does not drive air well, it will be necessary to disassemble the case in which the motor is located. Sometimes the fact that the propeller is not spinning can signal that there is insufficient lubrication in the plain bearing installed in the electric motor.The fan is disassembled as follows.

First you need to unscrew the protective mesh (its front part) and remove it.

After the net, detach the propeller.It can be screwed to the motor shaft with a left-hand thread nut. That is, to unscrew the nut, rotate it clockwise, and to tighten it - counterclockwise.

Remove the rear protective mesh by unscrewing another nut.

Unscrew all fasteners holding the unit cover. Sometimes there is another bolt in the handle to adjust the rotation of the body. If you do not unscrew it, you will not be able to remove the motor cover.

Now, when the engine is open, a few drops of engine oil should be dripped (it is better to use spindle oil) onto the bushing (indicated by a red arrow) and turn the shaft several times in different directions so that the grease is absorbed inside.

After this procedure, light rotation of the shaft is resumed. Reassemble the motor housing in reverse order.

Switch on the unit and check the air flow.

How to fix a floor fan if it has stopped spinning (turning) on the sides? It's all about crankthe fastening screws of which may loosen or come loose. To find out, you will need to disassemble the motor housing. If, during the operation of the unit, the body turns with a delay or a complete stop, then you should check gears in reducer for engagement. You also need to check the gear switch itself, namely, moving it up and down.

Disassemble the gearbox and remove the main gear. The shaft will also have to be pulled out. Apply grease to all moving parts and assemble the gearbox. If the gears are badly worn out, they need to be replaced, although it is quite difficult to find analogs for broken parts for the fan. In this case, you will have to assemble the unit without a gearbox and use the cooler as usual, when the air masses will move in one direction.

Cases when the fan does not spin and the motor hums are quite common. There may be several reasons for this breakdown:

lack of lubrication on the bearings (what to do, mentioned above);
failure of the capacitor;
malfunction of the electric motor.

Repair of the floor fan in this case comes down to checking the capacitance of the capacitor using a tester. To get to the radio component, you will need to disassemble the motor case. A detailed description of how to disassemble the case was given above. After removing the shroud, you will see a capacitor attached to the motor.

In the presented device, the capacitance of the capacitor is 0.85 microfarads. For this reason, the instrument must be set to a value in the range from 2 microfarads to 200 nanofarads, as shown in the figure below.

In this case, after connecting the capacitor to the device, you can see that its capacity is 0.841 microfarads. If we take into account the ± 5% error, then the capacity of the radio component is within the normal range, and it is not the reason that the cooler stopped working.

When repairing a fan with your own hands, in search of a breakdown it is also necessary to "ring" the electric motor. If it is faulty, the device will not turn on and will emit a hum. It is necessary to measure the resistance at two stator windings, having previously disconnected the wires going to them, as shown in the following figure.

As you can see, the resistance is also within the normal range, since its value is equal to 1215 Ohm (1.2 kOhm). Otherwise, the device will beep, but will not turn on. In such a situation, you will need to rewind the engine in a special workshop.

Since the propeller of the unit, whose main task is to create an air flow, is made of plastic (not always of high quality), the probability of deformation of the latter is high. This usually happens if the unit is left for a long time in direct sunlight or near a high temperature source. When deformed, the balance between the blades is disturbed, which causes strong vibration and noise during normal air flow.

Also, vibration of the shaft may appear due to the sleeve bearing bush that has become loose from prolonged operation.

Often, when the apparatus falls, when the blades are spinning, the protective grill is deformed... If a rotating propeller hits it, one of the blades may break.

Summing up, we can say that in different models of fans, the main units and control elements may look different. But the principles of diagnostics and troubleshooting do not change from this.

Desktop fan Mystery MSF-2428 REMOVAL AND REPAIR OF THE RADIATOR FAN ENGINE Well, that day came when the radiator fan began to fail, and what is most interesting, when the car in motion works normally. As soon as you get stuck in a traffic jam, or just stop with the engine running, the thermometer's arrow immediately creeps up, and you have to turn on the cabin stove to the full so as not to overheat the engine. I discovered this back in the fall, when I did an oil change, and flushed the engine. I left it to work, it was time to drain the oil, I climb into the salon to drive the car into the garage, wow, the coolant temperature is already critical. I opened the hood, and I see that the fan does not rotate. The first thing I thought about was the fan relay, which is on the front panel on the shelf above the radiator. In the old old fashioned way. Cracking his fist on the panel, it worked. Later it turned out that it was not the relay that was to blame, but the radiator fan motor - it fell into a dead center from which it could not start. On the move with the flow of incoming air, the fan impeller rotates the shaft, moving it off the dead center.A little about the design of the engine. There are two engine options that I have encountered.Two collector. Such a miracle. Where one manifold is located above the other, on the motor shaft. Accordingly, the speed of rotation of the motor shaft is controlled by supplying a supply voltage either to winding 1 or to winding 2. In this embodiment, the brush assembly consists of 8 brushes located in two levels on the carrier platform. Each pair of brushes is crosswise.The wires supplying power to the engine of red, green (+ 12 Volts go through them) and black (ground) are embedded directly into the engine case.One collector motor. Accordingly, one high-speed. The first speed is realized due to the inclusion of an external extinguishing ceramic resistance in the motor power circuit. It is fixed on the stiffening rib of the fan grill (shown in the photo with a red arrow). The second speed connects 100% of the onboard power supply to the motor via a relay.The wires supplying power to the engine are red (+12 Volts) and black (ground). The green wire (the first speed of rotation of the motor) goes into the damping resistor (shown in the photo with a red arrow). Fan relay (with corresponding markings on the case) in the lower left corner of the photo.How to repair In my case, the motor made according to the first option was faulty. (with two collectors).Work order: Removing the radiator fan.

disconnect the battery.

unscrew the 4 self-tapping screws securing the fan casing to the front panel (located on the sides of the relay and valve shelves)

disconnect all electrical connectors supplying power to the relays and valves. Do not touch the vacuum tubes !!

tilt the fan shroud towards the engine and remove the shelf with relays and valves, lay it on the fuel rail

undo the two ties on the casing body and pull the cable out of the clamps.

Tilt the radiator cowl towards the engine and pull it upwards.

Dismantling the fan motor.

do not unscrew the fan from the casing, this is more convenient.

remove the split washer from the motor shaft by hooking it up with a flat-blade screwdriver.

Turn the radiator cover over so that the impeller is at the bottom.

through the honeycomb of the casing, pushing the blades down and swinging the impeller, remove it from the motor shaft.Intercept the impeller periodically crosswise for a smoother removal from the shaft, and to prevent its deformation.

remove the brackets securing the wiring harness to the casing by hooking them up with a flat-blade screwdriver.

unscrew 3 pcs of large self-tapping screws securing the engine to the casing.

pull the engine out of the shroud.

tap on the exposed parts of the engine housing in order to remove the engine cover.

knock the cover off the housing elements.

remove the blue plastic washer from the engine shaft (remember its position with the skirt upward from the manifold)

squeeze and loosen the springs of the pressing brushes to the collector.

remove the brush board by picking it up with a flat-blade screwdriver.

Engine repair.

check how the brushes work, whether they move easily in the body.

clean them from deposits and wear products, treat with WD40.

check if the rotor of the motor rotates easily in the bearing.

grease the bearings.
if necessary, replace it; for this you will have to press or remove the fan base from the motor shaft with a puller. (I didn't do it)

Assembling the engine.

there is one trick. the brushes of the second tier must be fixed by inserting objects of suitable diameter (for example, matches, or toothpicks) into the holes next to the springs

put the board with brushes on the motor shaft
align the projections of the board with the slots in the motor housing.

snap the board into the housing and pull out the brush clips. (the brushes are brought to the collector, do not allow the board to be removed, otherwise repeat the operation from the beginning, otherwise the brushes may be destroyed or damaged)

bring the springs by pressing the brushes against the collector on the first tier.
check if all the brushes have come to the collector by ringing a pair with a tester (between black and red, between black and green wires). Or by raising the brush holder board by 2-3mm and look into the motor housing. In my case, on the inner tier, one of the brushes did not immediately come out to the collector, because the spring caught on the plastic housing and did not apply pressure to the brush. The brush is stuck.

put the motor cover on the shaft, aligning the slots in the cover with the projections on the motor housing.
by tapping on the circumference, push the lid back into place.

chisel the protrusions with a chisel, thus fixing the engine cover.
check the operation of the engine by supplying power to the wires going to the engine:

red - plus 12 volts maximum engine speed.

green - plus 12 volts minimum engine speed.

ATTENTION . Do not apply +12 V to the red and green wires at the same time.

Fan installation and assembly.

reassemble in reverse order

Thus, today 10.04.05 is saved from $ 570 (original from Volvo) - $ 250 (original from Bosch). You can also get China for $ 177, feel the difference.

Attention! Car service network of favorable prices. Camber check is FREE! No queues! Repair on the same day!

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In this article we will consider such a process as removing the radiator fan VAZ 2110. Why remove it? Well, there can be many reasons - from malfunctions of the fan itself, ending with getting to the radiator.

What is required for such a repair? Just a 10-key and a Phillips screwdriver.

First of all, we prepare the car for removing the fan, for this:

We partially drain the antifreeze so that you can unscrew the upper radiator pipe and coolant does not pour from it.
We fold the terminals from the battery and remove it.
We tear off the air filter housing from the rubber clips. For convenience, so that it does not interfere at all, we unscrew the clamp of the connecting pipe and disconnect the falsified corrugation from below.