Subject: The way of repair of electromagnetic clutch coil of the air conditioner compressor

Good evening, folks! I will share the way I managed to restore electromagnetic clutch of the compressor of my Zexel air conditioner. Background. In the fall of 2017, I started to hear a noise around the compressor when the engine was running. When I turned on the climate control, the sound disappeared. It is clear that the bearing of the muff of the compressor is worn out. Didn’t have much time, drove for a while with this malfunction. Drove until at another stoplight I noticed smoke coming from under the hood. Quickly pulled over to the side of the road, opened the hood. Smells like burnt wiring, source of the smoke. around the compressor. Skewed pulley is rubbing the solenoid and overheating it. You need to remove the belt. And how? It is tight, you can’t unscrew the tensioner on the road. In the end I took a knife and cut the belt and thus freed the compressor. The service re-pressurized the bearing and found that the solenoid was completely dead. The picture is not pretty. The coupling was removed.

Took out the old charred wire, cleaned the case.

Its internal dimensions are such that the coil cross section should not be rectangular, but trapezoidal. This prevented me from winding the coil on a simple mandrel (although I could probably try).

Measurements, searches on the Internet and simple calculations allowed to determine the parameters of the coil: resistance. 4 Ohms, wire cross section. 0.7 mm, number of turns. 300. Quite a manageable coil for hand winding. All that’s left is to figure out what to wind it on. Four years disassembled muff neatly lay in the closet. And not so long ago YouTube threw a recommendation for the manufacture of a “cold foghorn”. Turns out it’s such a hobby for a whole bunch of women. They make this headlight, and then mold flowers out of it. roses, tulips, leaves, etc.ะด. With the coloring and after drying is very realistic. So I thought. This is what you can use to make a template for winding the coil. This faor. Plastic material, made mostly by mixing good PVA, gypsum putty and starch. There may be various other additives. Molds easily, holds its shape, dries to an almost stony state at room temperature. There are a lot of recipes on the internet. In general, I stuffed the inner cavity of the socket under the coil with this torus. After drying, extracted. It turned out such a workpiece:

I wrapped black duct tape around it for strength. Then I stuffed it on the inside in the same way. After it dried, took out this second piece, which was shaped like a coil to be wound on it.

Here I corrected its size with a paper adhesive tape, to make it easier for the future coil to be inserted in the slots.

Then from two jar lids and three screws I made a mandrel for winding the coil:

After that I coiled up my coil, gluing the coils with painter’s tape. It turned out 340 turns and 4.3 ohms (it could be less, because it was hard to get into place). As a result, such coil has turned out:

Placed the coil in the clutch housing, put the wires out, wired it properly, and waxed it all up with epoxy. I don’t have a final photo, but it’s clear as it is. I installed everything on the compressor, without forgetting about adjusting washers for the pressure plate. Test connection to battery power showed that the pressure plate is perfectly magnetized to the pulley. Yesterday in the service, put a new belt and filled the system with freon and oil. Drove it today. everything is working perfectly! When parked with the engine running and the climate on. a lot of condensation collects under the car. In the cabin. pleasant coolness!

Car air conditioner: how to understand if it works or not?

With the onset of warm summer weather, being in a car often gets hot and uncomfortable. The air conditioner or climate control system keeps the optimal temperature in the cabin.

Air conditioner is a set of devices, which cools the interior of a car by changing the temperature of the coolant (gas). There is an opinion that air conditioner cools worse than climate-control. In fact, there is only one difference between them: if a car is equipped with conventional air conditioning, you yourself change the temperature of air flow colder / warmer, in the case of climate control, you set the temperature, for example, 20 degrees, and it is maintained all the time.

When buying a car, to the question: “Does the air conditioner work??”, the answer is often: “Yes, you just have to fill it up!”But, unfortunately, it may not be so simple, so you should not believe such statements. It costs not much to fill it up, so you can most probably say that if it’s not filled up, there are leaks and defects in it.

Simply refueling the air conditioning system after a long stay in a leaky and / or not charged, without diagnostics and troubleshooting, can lead to failure of an expensive compressor or its other elements.

To determine if the air conditioning system is faulty, let’s analyze what it consists of and how it functions?


Modern cars use freon r134a gas, as it has the best temperature dependence on pressure: with increasing pressure the temperature increases, with decreasing. on the contrary. Freon is not inflammable, and relatively easy to produce, that’s why it is so widespread.

For proper and full functioning of a conditioner, it is necessary to lubricate it with oil dissolved in freon.

It is different for different kinds of compressors (domestic, industrial, automobile), that is why freon is different, and one must not charge, for example, the system of home air conditioner with gas for a car one and vice versa.


The main and the most expensive knot. Piston or plunger pump that compresses gas in the system to 10-15 bar of pressure, has a pulley with a drive belt from the crankshaft. Two high and low pressure lines leading to and from evaporator.


Air conditioner radiator, located in the radiator cassette first just behind the front bumper. Incoming air stream or fan cools hot gas that enters it under pressure from compressor and turns into a liquid.

Drying filter

Contains silica gel that absorbs moisture from liquid Freon that is harmful to the system. On modern cars doesn’t need to be replaced for the whole period of operation.

Thermostatic pressure regulator (throttle)

Is installed directly on the evaporator in the cabin or at the junction of the tubes with the engine shield. Diffuses cooled freon from the liquid partially into a gaseous state, evaporating it into the evaporator. The gas pressure, as well as the temperature, drops dramatically (to about.2 degrees).


Radiator installed in the cabin (inside the torpedo), from which the cold air is supplied to the cabin. From the evaporator, the low pressure tube sucks freon back into the compressor.

How to check conditioner efficiency?

How to check any conditioner in a minute? Start the car, turn on the air conditioner. Next, near the compressor or throttle, just touch the two line pipes: high pressure (thicker) and low pressure (thinner).

The high-pressure tube should be hot (about 50 degrees) and the low-pressure tube should be cold (about zero).

If there is not enough gas in the system, or it is not tight, or compressor is defective, the temperature of tubes is the same, and that means that air conditioner will not work.

Old type car compressors work in two positions: on. and off., The new types have a stepless regulation. It promotes decrease of loading of engine and fuel economy.

Loading can vary depending on the temperature in the cabin and the engine speed: if you suddenly press the gas (for example, when overtaking), the compressor can even turn off, allowing the entire power of the engine to the wheels. The pressure in the air conditioning system does not depend on the amount of gas, but on its temperature.

Exactly for this reason freon is filled by kilograms. Even with smallest quantity of gas, conditioner will start, but it will cool down badly and the compressor will fail fast. Excessive quantity of gas is also harmful: freon will not have time to evaporate in the evaporator and in a liquid condition will get into the compressor that will lead to its fatal breakage.

For these reasons it is necessary to charge system of conditioning strictly specified by manufacturer, and only at specialized service stations and car-care centers, taking into account quantity of gas, remained in charging tubes (usually it is about 50 gr.).

For preventive purposes it is necessary to switch on air conditioner even in winter, preliminarily heating up interior, and then switching on cold air; and to prevent corrosion of pipes and joints, keep cleanness under a cowl, then a conditioner will serve for a long time without failures, and a salon will please with coolness even in the hottest day.

The clutch on the air conditioner compressor isn’t pulling

I think the pre and relay is okay, because when you press the button light turns on and the speed tends to go up from idle. And it may be that there is not enough current. How to check in this case. And find out exactly what’s causing the problem?

I think the fuse and relay are fine because when you press the button light comes on and the speed tends to go up from idle. It could also be that there is not enough current. How to check in such a case? And find out exactly what’s causing the problem?

The light will be on. These fuses and relays only work for the compressor. It may not have enough current. The clutch is triggered by an electromagnet. And its current consumption at the moment of switching on can be very high. If you want to check it that way, you should take voltage from the battery.

Malfunctions of the compressor and its repair with own hands. Car painting with your own hands

There are situations when the air compressor, peacefully rattling engine in the corner of the garage, begins to fail, and even turns off at all. And at this moment, as if by chance, it becomes necessary. Do not panic, after the study of theoretical information compressor repair with their own hands will not seem something unattainable.

Designation, basic elements and principle of operation

The main purpose of air compressor units is to create a continuous uniform stream of compressed air. The flow of dense gas in the future actuate a variety of pneumatic tools. These can be airbrush guns, tire inflation guns, wrenches, cut-off machines, pneumatic chisels, nail guns, etc. In the minimum set compressor unit is equipped with a blower (engine, creating a stream of air) and a receiver (capacity for storage of compressed gas).

The greatest use in car workshops have found compressors with an electric motor of reciprocating system.

In the supercharger crankcase, a transmission rod moves back and forth along the axis, transmitting an oscillating torque to the reciprocating motion of the piston and o-rings.

A by-pass valve system located in the cylinder head works so that as the piston moves down, air is drawn from the inlet port and released upward into the outlet port.

The gas flow is routed to a receiver where it is compacted. The supercharger produces an uneven jet of air due to its design. Which is not applicable to the use of the spray gun. The situation is saved by a kind of condenser (receiver), which smoothes the pulsations of pressure, giving at the output a steady flow.

A more complicated design of a compressor unit implies installation of additional equipment designed to ensure automatic operation, dehumidification and humidification.

And if in the case of a simple design it is easy to localize the fault, the complication of the design of the equipment makes it difficult to find.

The following are some of the most common malfunctions and solutions for the most common compressed gas systems with piston-type blowers.

Defects in the compressor system

To make it easier to find the problem, all defects can be classified according to the nature of the fault:

  • Compressor unit blower does not start
  • Compressor motor hums but does not pump air or fills air reservoir too slowly
  • Thermal fuse blows or blow mains fuse when starting
  • Lower pressure in the air vessels when the blower is switched off
  • Thermal circuit breaker intermittently actuates
  • There is a large amount of moisture in the outlet air flow
  • Engine vibrates strongly
  • Compressor does not run smoothly
  • Air flow rate is below standard

See all causes and solutions.

System blower does not start

The defective ones are replaced with passive protection devices of the same rating as the defective ones. Never allow fusible inserts that are designed for higher electrical currents. If the fuse blows again, determining the cause of the malfunction is likely to be a short in the circuit input.

Second reason for the unit not starting is the receiver pressure control switch is defective or the level settings are out of balance. Release gas from the cylinder and give the blower a test run. If the engine is running, the relay is reset. If this does not happen, the defective part must be replaced.

Also, the motor will not start if the overload circuit breaker trips. This device de-energizes the coil circuit of the electrical apparatus in the event of overheating of the piston system, which could cause the engine to seize. Allow the blower to cool for at least 15 minutes. After this time, perform a restart.

Motor is humming but does not run or at a low speed

If the mains voltage is too low, the electric motor cannot crank the axle and will hum. At this malfunction first of all check voltage level in your network with multimeter (it must be no less than 220 V).

If the voltage is normal, the pressure in the air reservoir is probably too high and the piston cannot push the air through.

In this case the producers recommend to set the automatic switch “AUTO-OFF” to “OFF” position for 15 seconds and then set it to “AUTO” position.

If it did not help, the pressure control relay in the air reservoir is defective or the by-pass (control) valve is clogged.

This last fault can be remedied by removing the cylinder head and cleaning the ducts. Replace faulty relay or send it to a specialized service center for repair.

Compressor start-up is accompanied by blowing the fuse or activation of the thermal protection automatics

This fault occurs if the installed fuse is below the recommended rating or if the mains supply is overloaded. In the first case, check the permissible currents; in the second case, disconnect some consumers from the electric line.

serious reason of trouble is incorrect work of voltage relay or breakage of overflow valve. Bypass the scheme of relay contacts, if the engine is running, it means that the executive device is faulty. In this case it is more reasonable to apply for technical support to an official service center or replace relay independently.

electromagnetic, clutch, conditioner, compressor

When supply voltage is disconnected air pressure drops in receiver

Decrease of compressed air pressure indicates that there is a leak somewhere in the system. Areas at risk: high pressure air line, piston head check valve or receiver bleed valve. Check all piping with soapy water for air leaks. Detected defects are wrapped with sealing tape. [/spoiler]

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