The VAZ-2110 cooling fan does not work. Cooling fan activation circuit

To ensure the safe and stable thermal conditions of the internal combustion engine requires a clear operation of the cooling system. The slightest failure will lead to overheating of the motor, which is fraught with burn-out of the head gasket of the BC or the failure of the elements of the piston group.

The radiator fan is one of the key components of the car cooling system. Its role is to promptly forcibly cool the liquid in the radiator. Problems with its inclusion are not uncommon for our machines.

In this article, we'll talk about the possible reasons why the VAZ-2110 cooling fan does not work , and also consider options for their elimination. But first let's look at its design and principle of operation.

What is a radiator fan

Constructively the radiator fan consists of:

• Frame (frame);
• Drive (electric motor);
• Impeller.

The electric motor with an impeller on the shaft is mounted inside a rectangular metal frame, by means of which it is fixed to the rear side of the radiator. When the voltage is applied (12 V) to the contacts of the drive, it starts to work by rotating the blades and creating a directed stream of air, which, in fact, cools the antifreeze or antifreeze.

Scheme of the fan in the carburetor and injector engines

Controlling forced cooling of the radiator in carburetor and injector engines VAZ-2110 is very different. In the first for everything, the fan switch is located on the radiator housing. It is tuned to a certain temperature of the coolant (coolant). Typically, this is 105-107 ^o C. When the coolant is heated to this temperature, the sensor responds by sending a signal to the fan relay. It also closes the electric circuit, activating the electric motor.

The inclusion of a cooling fan VAZ-2110 with an injector motor is somewhat different. In engines equipped with an electronic control unit, there is no sensor on the radiator. Its place was occupied by the temperature sensor located on the nozzle of the thermostat. When the coolant is heated to a temperature of 105-107 ° C, it sends a signal directly to the controller, which makes the decision to turn on the fan. It transmits an electrical impulse to the relay, which turns on the electric drive.

Possible malfunctions

If the VAZ-2110 cooling fan does not work, do not rush to contact the auto service center. You can determine the cause of the problem yourself. Especially because it does not necessarily have to have special skills.

The cooling fan may not turn on due to:

• Malfunction of the electric drive;
• A blown fuse;
• Faulty thermostat;
• A failed fan switch (temperature);
• Faulty relay;
• Breakage of electrical wiring;
• A faulty expansion tank plug.

Checking the fan drive

A frequent reason why the VAZ-2110 cooling fan does not work is the malfunction of its drive (electric motor). It can be the wear of brushes, breakage or shorting of the windings, the absence of contact in the connector, etc. It is not difficult to check the drive. For this it is enough to disconnect the fan from the electric circuit of the car, and connect it directly to the battery. If it does not turn on, the problem is exactly in it, if the engine has started, the troubleshooting should be continued.

Fuse test

If the radiator cooling fan VAZ-2110 is working, the next step is to check the fuse. It is located in the engine compartment of the engine compartment and is designated F7 (20 A). The test is performed using a car tester (multimeter) included in the probe mode. If the test proves the inoperability of the fuse, it must be replaced.

How to check the thermostat

The function of the thermostat in the internal combustion engine is to regulate the flow of the cooling liquid, directing it either over a small or a large circle. While the motor is cold, its valve blocks the coolant flow to the cooling radiator. This allows the engine to warm up more quickly. When the coolant is heated, the thermostat valve opens, guiding it into the radiator for cooling. If the valve sticks, the coolant constantly moves in a small circle, not reaching either the fan switch or the temperature sensor. In this case, the liquid can even boil, but the sensors, if not used in this circuit, will not work.

Check the thermostat by determining the temperature of its nozzles to the touch. When the engine is warm, they must all be hot. If the pipe from the thermostat to the radiator is cold, the locking device is defective.

How to check the sensor

One of the most common reasons for not turning on the VAZ-2110 cooling fan is a non-working sensor for its inclusion (for carburetor engines) or a temperature sensor (for injectors). Let's consider ways of testing them for different engines.

In a car with a carburetor motor, you must turn on the ignition and close the two wires to the sensor. The fan should turn on. If this does not happen, the problem is definitely not in the sensor.

For the injector auto, the motor should warm up to operating temperature, and disconnect the sensor connector by disconnecting it from the vehicle's on-board network. In this case, the controller must run the fan in emergency mode. The electronic unit perceives this as a malfunction in the cooling system, and makes the fan drive operate in a constant mode. If the drive is started, the sensor is defective.

Checking the cooling fan relay

The most difficult stage of searching for a fan failure is determining the operability of its relay. To establish its serviceability at home can only be relatively. But we also need to know where the cooling fan relay is located.

And it is located in the additional mounting block of the center console. On the bottom left side of the front passenger there is a plastic cover covering the console. To open it, you need to unscrew the four screws. There are three relays under the cover. The activation of the cooling fan corresponds to the extreme left. You can verify it only by installing a known device in its place. After warming up the engine to the temperature of the sensor, we wait for a characteristic click. If the cooling fan relay does not work, check the wiring.

How to check wiring

Independently to find a breakage of a conductor in an electrical circuit of the car it is absolutely uncomplicated. It is necessary for the tester to check (ring) all the wires in the specified areas.

For carburetor engines:

• From the sensor to the fan;
• From the fan to the assembly block (fuse);
• From the mounting block to the relay.

For injection engines:

• From the main relay to the fan switch;
• From the relay of inclusion to the fan and the controller;
• From the temperature sensor to the controller;
• From the fan to the mounting block (fuse).

If the wiring is broken, it must be restored, and the possible cause of the circuit breakage should be identified and eliminated.

Expansion Tank Cover

The last reason why the VAZ-2110 cooling fan does not work may be a malfunction of the expansion tank cap. The fact is that when the engine is running, the pressure in the cooling system is higher than atmospheric pressure, so that the water that is part of the coolant does not boil at 100 ° C. The expansion tank cap valve is designed to maintain the desired pressure. If it fails, the pressure in the system will equal the atmospheric pressure. This will cause the coolant to begin to boil at 100 degrees. A sensor designed to switch on at a higher temperature naturally does not work.

Check the operation of the lid at home is unlikely to work, so if you have any doubts about its performance in a visual inspection, it is better to replace it immediately.