Installing an additional fan

Design and principle of operation

The designers of the Chevrolet Niva used a dual fan unit in the cooling system.
This slightly complicated the connection diagram, but sharply increased the efficiency of radiator airflow. The fans are driven by 12-volt DC synchronous motors with a permanent magnet inductor. Electric motors have a closed, non-demountable design and do not require maintenance. The power of each electric motor is 110 W. The fan assembly draws 18 amps.

The fans are turned on one by one using an electromagnetic relay controlled by the on-board computer. When the coolant heats up above 99 degrees, the electric fan located closer to the engine air intake starts. The switch-on temperature of the second impeller is 101 degrees. The fan connection diagram is shown below.

The fan power system includes three relays and a resistor, which, if necessary, provides a reduced rotation speed of the first motor. Power is supplied from the battery through fuses that save the wiring and battery in the event of a short circuit. Control signals come from pins 29 and 68 of the motor controller.

The fans automatically turn off when the antifreeze cools to 95 degrees.

Consecutive switching on and off of engines reduces the load on the on-board electrical network. In most cases, it is possible to normalize the temperature only with the help of the first fan. This is especially useful when driving at night, when headlights and side lights put a lot of stress on the generator.

The ability to force fans on can be useful when driving off-road or in city traffic jams. However, the designers of the Chevrolet Niva did not provide the car with this function. It can be implemented independently or at a service station. It is necessary to connect backup relays parallel to the switching contacts and power them from a button installed in the car interior.

Useful video about installing and connecting the forced fan button on the Shnivy:

Important: forced activation increases the reliability of the cooling system. In case of malfunctions of sensors, relays or on-board computer, the driver can manually turn on the radiator airflow.

It is useful to equip the Chevrolet Niva with a switch that forcibly turns off the fan motors. This will protect their blades when fording water obstacles.

Vehicle cooling network design

The cooling system of the VAZ Niva is quite effective and has undergone virtually no changes since its creation. It includes the following units and elements:

  1. Mechanical water pump (pump). Installed in the cylinder block on the front side, its impeller is immersed in coolant circulating through the water jacket of the VAZ-2121 engine. Driven by belt drive.
  2. Mechanical thermostatic element (thermostat). It is located on the right side of the block in the direction of travel. From it the pipes go to the water jacket and radiator.
  3. Cooling radiator with 2 plastic tanks on the sides. Located at the front of the car.
  4. Fan with air diffuser. Attached to the inside of the radiator.
  5. Expansion plastic tank with a lid equipped with valves. Connected by a pipe to the radiator.
  6. Interior heater heat exchanger equipped with a tap.

Temperature control in the Niva engine cooling network is carried out in different ways. In the carburetor model VAZ-21213, a sensor is built into the cylinder head, connected to the temperature indicator on the dashboard. On the VAZ-21214 model, where the fuel is supplied by an injector, there is a second sensor mounted in the pipe on the cylinder head. It is connected to a controller that prepares the fuel mixture depending on the heating of the power unit and turns on the fans.

There are 2 more differences in the cooling design of engines with a carburetor and an injector:

  • on cars with direct fuel injection, 2 electric fans are installed on the radiator instead of 1 mechanical;
  • The heating pipes for the lower part of the carburetor in model 21214 provide heating for the throttle body.

In VAZ-2131 Chevrolet Niva cars, the cooling system is generally similar to a regular Niva with an injector. The VAZ-2131 heater radiator is not equipped with a tap, which is why antifreeze flows through it all year round.

Circuit breakers

The electrical circuits of Niva Chevrolet cars produced before and after 2009 are different. In both cases, 50-amp fuses protecting the electric fan power circuits are located in an additional unit. It is located behind the glove box on the passenger side of the cabin. The figure shows where the fan fuses are located.

If the permissible current is exceeded, the insert melts and the circuit opens. Therefore, fuses are the first thing to check if the electric cooling fan does not work. The performance of a part can be assessed visually or using an ohmmeter (multimeter). To do this, you will first have to remove the fuse from the socket.

Fan relay

The additional block contains not only fuses. There are also three electromagnetic relays that control the operation of the electric motors of the cooling system. Their control circuits are powered from the ignition switch and on-board controller outputs, and the power current comes from the battery through fuses.

The relay operates as follows:

  1. Voltage is applied to the control terminals.
  2. Current passes through the inductor, resulting in an electromagnetic field.
  3. The steel contacts attract and close.
  4. The current passing through the relay drives the electric motor.

As soon as the control voltage disappears, the contacts open under the influence of the spring and the fan stops.

You can check the functionality of the relay in three ways:

  • Replace the relay with a known working one and test the operation of the system.
  • With the engine off and the ignition on, disconnect the temperature sensor connector. You should hear the relay click.
  • Dismantle and test the output contacts with a multimeter, applying voltage to the terminals of the induction coil.

Reasons why the cooling fan does not work on a Chevrolet Niva

To maintain the optimal temperature in the engine, a cooling system is installed in the car.
One of the main elements in this system are fans, thanks to which the required amount of air is supplied to the engine through the radiator core. If it stops working, the Niva Chevrolet cooling fan overheats as excess heat begins to accumulate. Unlike classic cars, it has two fans, making the functioning of the systems much more complicated. If the arrow that shows the temperature is in the red area, and the cooling system refuses to work, and at the same time the cooling fan does not turn on, then the car should be taken to a car service center as quickly as possible, or you should try to find the cause of the malfunction yourself.

Fans of the Niva Chevrolet cooling system are used for forced ventilation of the radiator. They increase the intensity of heat dissipation while driving at low speeds and are the only way to cool the antifreeze in a plug or “toffee”.

The electrical circuits of Niva Chevrolet cars produced before and after 2009 are different. In both cases, 50-amp fuses protecting the electric fan power circuits are located in an additional unit. It is located behind the glove box on the passenger side of the cabin. The figure shows where the fan fuses are located.

If the permissible current is exceeded, the insert melts and the circuit opens. Therefore, fuses are the first thing to check if the electric cooling fan does not work. The performance of a part can be assessed visually or using an ohmmeter (multimeter). To do this, you will first have to remove the fuse from the socket.

The additional block contains not only fuses. There are also three electromagnetic relays that control the operation of the electric motors of the cooling system. Their control circuits are powered from the ignition switch and on-board controller outputs, and the power current comes from the battery through fuses.

The relay operates as follows:

  1. Voltage is applied to the control terminals.
  2. Current passes through the inductor, resulting in an electromagnetic field.
  3. The steel contacts attract and close.
  4. The current passing through the relay drives the electric motor.

As soon as the control voltage disappears, the contacts open under the influence of the spring and the fan stops.

You can check the functionality of the relay in three ways:

  • Replace the relay with a known working one and test the operation of the system.
  • With the engine off and the ignition on, disconnect the temperature sensor connector. You should hear the relay click.
  • Dismantle and test the output contacts with a multimeter, applying voltage to the terminals of the induction coil.

The control unit receives information about the antifreeze temperature from a temperature sensor. It is a resistor whose resistance changes with heating and cooling: from 1.3-1.8 kOhm at 30℃ to 155-196 Ohm at 90℃. You can check its performance using an ohmmeter and a thermometer. To do this, you need to remove the part, immerse it in water and measure the resistance at different temperatures.

The sensor is located on the engine head in the area of ​​the exhaust pipe of the cooling system. You can unscrew it with a socket or socket wrench.

Everyone knows that modern cars have a water engine cooling system in their design, which allows many times to increase the service life of not only the engine, but also the entire mechanism as a whole. The Chevrolet Niva also has a radiator in its design that is filled with coolant.

This liquid circulates through the system, thereby cooling the car engine. But the engine temperature exceeds 100 degrees, so if this liquid is not cooled, it will soon turn from cooling to heating. This is precisely why there is a radiator cooling system, the operation of which is carried out by a fan.

But since the Chevrolet Niva is equipped with a powerful 1.7-liter engine, two fans are used to cool the radiator. In this article, we will look at how these devices work, or rather, what is the main element of turning on these devices on a Chevrolet Niva SUV.

The cooling fan is powered by a constant voltage of 12 V from the battery. They turn on when two sensors located in the engine reach a certain temperature. So, when the first sensor reaches a temperature of 99 degrees Celsius, it is triggered, which causes the first fan to turn on.

It has two rotation speed positions - high and low rotation speeds. When the second sensor reaches a value of 101 degrees, then, accordingly, the second device turns on. Thus, the cooling devices of the Chevrolet Niva engine are briefly activated. But we are interested in what role such a small device as a relay, of which there are three on the Chevrolet Niva, plays in this process.

The radiator cooling fan does not work (does not turn on) - reasons, troubleshooting

— blown, check the fuse that controls the fan

— the fan switch sensor (DVS) is faulty

- faulty fan relay

- faulty fuse box

- power cable break

— break in the output path to the radiator sensor wire

— the gasket under the head is burned out (coolant does not pass into the cylinder)

Problems with the cooling fan usually occur in used cars with decent mileage. This breakdown manifests itself in different ways; the fan may not work stably, may turn on late or not turn on at all.

There can be quite a few reasons why the fan does not turn on, from a banal fuse blown to more complex problems associated with a malfunction of the thermostat or problems with the electrical wiring of the vehicle's on-board network.

If the engine boils, but the fan still 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. The device designed to monitor 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.

Also interesting: Headlight diagram and lighting Niva 2121, Niva 2131

Then check the fuse that controls the fan; if the fuse is blown, replace it with a intact one. If the cause is not a fuse, you need to check the fan itself directly. The power wires come to it; often they simply crumble or break off due to age. Alternatively, the reason may lie in the plug, so if everything is fine with the wiring, turn off the power to the fan and check the plug for a malfunction. Connect 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.

Check the fan switch sensor (FSW) located on the radiator. To do this, you need to disconnect the plugs and then connect them together; if the fan does not work, the DVV is faulty and requires replacement.

It is necessary to connect the wire going to the fuse box directly to ground (usually white with a black stripe). If after this the fan starts working, we can conclude that the second black wire has broken; try to find the 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 quite possible that the problem is there. In order to find out, simply replace it with an adjacent relay, then connect the radiator sensor wires to each other, see above. The fan will turn on - the problem is a faulty relay.

Next, you need to check the voltage to see if it is supplied to the fan through the fuse box. To do this, take a piece of wire and install it in the relay connectors; if the fan is working, 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 “old-fashioned” method. We take a light bulb that will serve as a “control”. If there is no light bulb, just lightly strike the other end of the wire against ground, 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 block.

If, after checking all of the above, you find the reason why the radiator fan does not turn on, you only have to check one wire - the radiator sensor wire. To do this, you must remove the switch as it does not allow access to the fuse box plugs. This means we remove the plug from the fuse block and check the radiator sensor wire for a break.

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

If the fan does not turn on, the reason may be completely unexpected, for example, a burnt gasket under the head. Switching on does not occur for the reason that the coolant does not enter the cylinder, while gases from the cylinder penetrate into the coolant, creating an effect known as an air lock.

WHAT TO DO IF THE RADIATOR COOLING FAN DOES NOT WORK

Power sensor

The control unit receives information about the antifreeze temperature from a temperature sensor. It is a resistor whose resistance changes with heating and cooling: from 1.3-1.8 kOhm at 30℃ to 155-196 Ohm at 90℃. You can check its performance using an ohmmeter and a thermometer. To do this, you need to remove the part, immerse it in water and measure the resistance at different temperatures.

The sensor is located on the engine head in the area of ​​the exhaust pipe of the cooling system. You can unscrew it with a socket or socket wrench.

We recommend watching a video that shows where the sensor is located and how to check:

Possible faults

To avoid problems with engine overheating, it is necessary to monitor and maintain the Niva’s cooling system.

You should check the antifreeze level in the expansion tank more often. Due to the reliability of cooling, there are not many malfunctions in it:

  1. When the car heats up to maximum in any weather, and the main radiator pipes are cold, the thermostat has broken. The element is not repaired, only changed.
  2. Electric fans turn on at random, including when the engine is cold, but if they overheat, they may not start. This means that the sensor transmitting temperature data to the controller has failed and must be replaced.
  3. When the indicator on the panel gives inaccurate data or does not show the temperature, you need to change the second sensor located in the cylinder head.
  4. The fluid level in the tank is constantly decreasing. It is necessary to look for and eliminate leaks in the pipes or in one of the radiators.

It is important to periodically check for play in the water pump shaft. Its appearance indicates wear of the bearing; it is necessary to change the pump as soon as possible.

The connection diagram for Niva VAZ-21214 fans is identical to the diagram for other cars of the VAZ family. The only difference is the presence of two fans, which are turned on using two relays. This is caused by the engine working under heavy loads when driving off-road. In city conditions this is practically not necessary, with the possible exception of driving in traffic jams in hot weather. When turned on, fans create some discomfort as they make noise. You can reduce noise by reducing the rotation speed of the electric motors or turning off one of the fans. In the second case, the second fan can be turned on forcibly using a button or key.

Possible malfunctions and their causes

1.Both fans do not work. The electric motors may fail, the temperature sensor may malfunction, or the power wires coming from the battery or ignition switch may be broken.

2. The second fan does not work. Causes: sensor malfunction, fuse or electromagnetic relay failure. It is also possible that the power cable may be broken.

3. The left fan does not turn on. Causes: faulty power resistor or temperature sensor, blown fuse or relay. It is also possible that the power cable may be broken.

4. Only two fans turn on at a time. This happens when an additional resistor in the circuit of the first electric motor breaks.

5. The fan does not turn off. Typically, the fan runs constantly when the relay is broken or the coolant temperature sensor is faulty.

Repair of fans, sensor, relays, fuses and additional resistor is not provided. If these parts break, they should be replaced with new ones.

Fan malfunctions

Let's look at what malfunctions of the Niva cooling fan may occur and how to identify them. The most common malfunction is blown fuses.

The fuse blows.

A single occurrence of such a malfunction does not indicate a faulty wiring or the fans themselves. During operation, fuses heat up and eventually fail. They are easy enough to replace. They are located on a carburetor car in the lower fuse block, and on an injection car in an additional block near the driver's door pillar.

If the fuses blow immediately when the fans are turned on, then it is necessary to find a short circuit or replace the fan. To determine the location of the malfunction, it is enough to disconnect the connector on the fan motor and connect the wires on the radiator sensor with each other with the ignition on.

On an injection engine, to check it is necessary to remove the chip from the temperature sensor, which is located on the thermostat. In this case, the engine control unit will go into emergency mode and activate a program for working with a faulty temperature sensor and turn on the fan relay. If the fuse burns out, then it is necessary to find and eliminate the short circuit. If the fuse remains intact, then the problem is most likely in the fan motor. Faulty fans are stuck or difficult to rotate. This may be caused by the stator magnet falling off or the armature bushings wearing out. A faulty fan should be replaced.

The fan does not turn on

Another common malfunction is when the fan does not turn on when the operating temperature is reached. The reason may be a malfunction of the fan sensor on a carburetor car or the engine control unit on an injection car, a relay malfunction, broken wires, or a malfunction of the fan motor.

It is better to start troubleshooting by checking the temperature sensor or control unit. This is done as described earlier by bridging the wires on the carburetor engine sensor or removing the chip from the temperature sensor on the injection engine. If the fans do not work, then you need to check the power relay.

The relays are located under the instrument panel on the front wall. To check, remove the chip from the relay and check for the presence of power at pins 30 and 85. If there is no power, check the condition of the fuse and wires. If there is power, connect terminals 84 and 85 of the relay with a test lamp. If the warning lamp does not light up, then the wire from the ECU connector to the relay socket is broken or the ECU itself is faulty. A lit lamp indicates a relay malfunction.

To test the relay, connect pins 87 and 30 with a piece of copper wire, which should trigger the fans. If this does not happen, then connect a test lamp to the connector without removing the jumper from the relay connector. If the lamp does not light up, then connect one end of the test lamp to the housing, and with the other, check for the presence of a plus on the connector. If the control lamp does not light up, then there is a break in the wire from the relay to the fan connector. Accordingly, the glow of the lamp indicates poor contact of the negative wire with the body or a wire break. The presence of power and minus indicates a malfunction of the electric motor.

Correct operation of VAZ NIVA radiator cooling fans. Fan switching temperature +95+98 degrees. The duration of operation of the fans depends on the ambient temperature and the condition (serviceability of all components) of the engine cooling system. If the fans do not work normally for a long time, then, if necessary, you can find the reason. I talked about this in previous videos. Links below in the description: How to remove an air lock on a VAZ NIVA. Correctly removing the air lock on a VAZ NIVA

Checking the VAZ NIVA thermostat without removing it. Choosing a VAZ NIVA thermostat All signs of a broken cylinder head gasket on a VAZ NIVA. At all stages of head gasket failure

Signs of a pump malfunction. Choosing a VAZ pump. VAZ NIVA pump design. All reasons for engine overheating and boiling. Eliminating the causes of VAZ NIVA engine overheating

Details. Why the cooling fans of the NIVA VAZ radiator do not turn on. Ideal inclusion and operation of the VAZ NIVA fans. Radiator cooling fan switching temperature

Andrey, do you have standard fans? They don’t seem to buzz as loudly as our 2131. When ours starts howling, you can hear it a kilometer away. True, judging by the dashboard, your car is older than ours (ours is 2013), but your fans are also electric and visually similar to those on our Niva. Have you encountered such a situation? 

Oh, these fans are disgusting, they howl so that you immediately understand that somewhere in a traffic jam a Niva is driving, and how they attract the attention of your neighbors downstream. They all howl the same way, it’s just that from the video it seems quieter. But this is the question I have in the M-ka 2014: when I fill up with fuel, the arrow does not reach the maximum when the tank is full, is this the case for everyone? Another question is when half or a quarter of the gasoline is filled, the smell of gasoline appears in the cabin, but it is not obvious, but with a full tank everything is normal and there are no odors. 

Niva21214 2000, Fans work without noise. Why. 

So what switch-on temperature is considered correct and safe for the engine.. You can set it to at least 90 on the BC. 

Thanks Andrey. Yesterday I tested the Niva off-road) the fans work, they turn on only when the needle approaches 130, and somehow quickly turn off, literally 40 seconds and that’s it. When is the next video)? 

For +gruzchik79. Hello. The operating temperature is +90C, but the fans should be turned on according to the standard at +95+98C - this is for more complete combustion of fuel. For materials, the safest engine temperature is generally +85C. Set it to +85C, only if your thermostat opens at +87C, then why should the fans turn on at +85? And +90C is too early. At 2112 at +101C it turns on and at 97-98 it turns off. The fan switch-on temperature on the latest generation VAZ 2110 -2112 engines is generally (100-105 C). It is too high compared to the normal operating temperature of the engine (85-90 C). This innovation is related to the manufacturer’s struggle for cleaner exhaust from the pipe (requirements of modern Euro 3 standards and higher). At this temperature, more complete combustion of fuel and its components occurs, but the load on metal, plastic, rubber, wires is greater and, as a result, wear is faster. Therefore, 95-98 is optimal (ideal) in my opinion. But you can do +90. Nobody forbids it. Everyone decides for themselves. 

matte 159 rus

Hello Andrey, maybe you know what the problem is and tell me I came into the car in the morning in the evening it was raining and found water on the floor at the driver’s feet and on the box where the receipt was stuck, I touched under the panel, it seemed like everything was dry, where the water could have come from, I still don’t understand, thanks in advance

Hello Andrey, I encountered the following problem: the left fan (on the driver’s side) does not turn on; I connected the screw in a straight line in order, but the right one turns on at 100+, what could be the problem?

matte 159 rus

Hello, forgive me for contacting me so often, for some reason, at one point, 1 fan did not turn off and continued to work for about 30 minutes, I turned off the car, removed the terminal, it still did not turn off, and when I turned it off, it continued to work, while the terminal was turning it off, I took out the fuse, and then it stalled waited about 15 minutes, inserted the fuse, the fan started working again, turned the ignition key, the fan stopped working, didn’t understand anything, drove on, “NIVA URBAN” (for sale if anything :).)

Replacing fans

If the fan motors do not start when the wires from the battery are connected directly to the power terminals, the devices must be replaced.

To do this, you will need a set of wrenches ranging in size from 10 to 17 mm and a Phillips screwdriver.

Before starting work, you need to drive the car onto an inspection ditch or a lift and turn off the power to the on-board network by removing the negative terminal of the battery.

Fans are dismantled as follows:

  • Remove the crankcase protection and mud guard.
  • Unscrew the screws and remove the thick spider-shaped plate and a couple of tin covers that are located in front under the bottom of the car.
  • Unscrew the radiator frame cross member.
  • Loosen the tension and remove the power steering belt and pump.
  • Remove the 4 bolts holding the power steering pump.

Useful video showing how to remove and change fans:

Important: to get to the bolt covered by the oil filter, you need to move the amplifier away from the bracket.

  • Push the pump back, hanging it on the hoses.
  • Remove the air conditioner drive belt.
  • Remove the bolt holding the timing belt pulley.
  • Remove the pulley and belt.
  • Unscrew the four nuts at the corners of the electric fan housing and the two bolts securing it in the middle.
  • Remove the fan unit from the studs and pull it down.

Tip: The crankshaft position sensor makes it difficult to remove the fans. Therefore, they need to be pulled out gradually. The left side is lowered first, then the block is moved to the left, raising the right edge so that the casing becomes vertical.

This method is probably suitable for restyled Niva Chevrolet models. On older cars, you will have to remove the radiator grille and bumper, unscrew the fasteners and move the air conditioning and cooling radiators forward. After this, access to the electric fans will be open.

During dismantling, you should carefully remember the procedure. Assembly is carried out in reverse order.

Important: the service life of the fan motors is approximately the same. Therefore, even if one of them fails, both must be replaced. Otherwise, you will soon have to repair the car again.

The main elements of the system and what are the benefits of silicone pipes

The details of the system are presented in the diagram above, these include:

  • air cooling radiator (art. 2123-1301012);
  • casing with fans (art. 2123-1300025-01);
  • temperature sensor (art. 2101-3808600-02 and 2112-3851010);
  • water pump (art. 2123-1307010);
  • thermostat (art. 2123-1306010);
  • pump (art. 21230-1307011-82).

All elements of the cooling system are connected to each other through various hoses and pipes, which in most cases are made of rubber or polymers with similar properties.

As a reasonable alternative to rubber hoses, car enthusiasts increasingly prefer silicone analogues, which are significantly more expensive. The main reason for this is that silicone does not “tan” in the cold and does not crack. This allows you to avoid coolant leaking out of the system, which significantly affects the efficiency of its operation. Completeness of the Chevrolet Niva cooling system pipes:

  • Upper radiator hose - 1 piece;
  • Lower radiator hose - 1 piece;
  • Thermostat and water pump pipe 1 piece;
  • Heater radiator supply hose;
  • Heater radiator outlet hose.

The strength of the silicone itself largely depends on the thickness of the tube walls, as well as the presence of special reinforcement. Parts made from this material, made specifically for cooling systems, are often characterized by double reinforcement, which makes their design much stronger and more durable.

If you believe the reviews of the Shniva owners themselves, then all the additional costs of replacing rubber cooling pipes with silicone ones are completely justified. This is especially true if the car is operated in harsh northern conditions.

It should also be noted that in most cases the connections are clamped with spring clamps and only in rare cases are screw clamps used. Another undoubted advantage of silicone is the fact that it resists the effects of gasoline well without changing its physical properties.

The circulation of antifreeze or antifreeze in the Chevy Niva cooling system occurs in two circles - small and large. In the first case, the liquid moves bypassing the radiator, since it does not need additional cooling and the outside air temperature is sufficient for it to effectively absorb heat from the engine. The tolerance for the heating level of the liquid in this case is about 78 degrees Celsius.

The standard pressure level is 1-1.2 atmospheres, and when the liquid is heated, its excess is “bleeded off” through a special valve. It is located on the expansion tank, which can be further adjusted.

If heating occurs above 80 degrees, liquid circulation begins in a large circle, involving the radiator in cooling. The direction of liquid movement in one of the circles is regulated by a thermostat, which reacts to an increase in the temperature of the liquid in the system, opening and closing if necessary. In this case, circulation is provided by a water pump, which is driven by the crankshaft through a special V-ribbed belt.

Also interesting: Replacing the knock sensor in a Chevrolet Niva: where it is located, how to check where it is located in a Chevy Niva, signs of malfunction and location features

Cooling of the cylinder head and block occurs due to a special “jacket” with coolant, which picks up heat and then enters the radiator, where its temperature decreases. To ensure complete tightness of the system and prevent fluid leakage, a gasket and seal are provided. The first ensures tightness on the side of the cylinder block, and the second prevents leakage at the point where the shaft enters the pump housing.

When the liquid circulates in a large circle, it is cooled by the radiator honeycombs, which are blown by the air flow. In most cases, this is quite enough to provide the necessary heat transfer. However, in the hot season or in traffic jams at low speeds, the temperature of the antifreeze increases significantly, until the liquid completely boils.

In this case, the heating is regulated by forcibly turning on the fans, which are attached to the radiator housing from the outside. The factory design provides for the presence of two such elements at once, which are activated independently of each other. The first is when the liquid is heated to 98 degrees, the second - to 102.

The efficiency of the fans is guaranteed only if the temperature sensor inside the radiator is working properly, the readings of which serve as the reason for starting the active air cooling system. In this case, the normal operating temperature of the liquid is considered to be from 80 to 95 degrees.

The designers of the Chevrolet Niva used a dual fan unit in the cooling system. This slightly complicated the connection diagram, but sharply increased the efficiency of radiator airflow. The fans are driven by 12-volt DC synchronous motors with a permanent magnet inductor. Electric motors have a closed, non-demountable design and do not require maintenance.

The power of each electric motor is 110 W. The fan assembly draws 18 amps.

The fans are turned on one by one using an electromagnetic relay controlled by the on-board computer. When the coolant heats up above 99 degrees, the electric fan located closer to the engine air intake starts. The switch-on temperature of the second impeller is 101 degrees. The fan connection diagram is shown below.

The fan power system includes three relays and a resistor, which, if necessary, provides a reduced rotation speed of the first motor. Power is supplied from the battery through fuses that save the wiring and battery in the event of a short circuit. Control signals come from pins 29 and 68 of the motor controller.

Consecutive switching on and off of engines reduces the load on the on-board electrical network. In most cases, it is possible to normalize the temperature only with the help of the first fan. This is especially useful when driving at night, when headlights and side lights put a lot of stress on the generator.

The ability to force fans on can be useful when driving off-road or in city traffic jams. However, the designers of the Chevrolet Niva did not provide the car with this function. It can be implemented independently or at a service station. It is necessary to connect backup relays parallel to the switching contacts and power them from a button installed in the car interior.

It is useful to equip the Chevrolet Niva with a switch that forcibly turns off the fan motors. This will protect their blades when fording water obstacles.

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