The situation when on a hot summer day air-conditioner ceases to perform its function, turning the cabin into a hot greenhouse, familiar to many drivers. Instead of the expected cool breeze, warm air blows from the deflectors, which not only reduces comfort, but can also be dangerous to health, causing heat stroke or loss of concentration. In such cases, it is important not to panic, but to consistently analyze the possible causes of the malfunction.
The efficiency of the air conditioning system depends on many factors, ranging from the amount of refrigerant in the circuit and ending with the serviceability of the electrical control circuits. Climate control And conventional air conditioning have a similar design, but in the first case, an electronics unit is added, which can also be a source of problems. Understanding the principles of operation will help you quickly diagnose a breakdown or make an informed decision about a trip to the service.
In this article, we will explain in detail why air conditioner doesn't chillWhat nodes fail most often and whether it is possible to fix the problem yourself. Ignoring the first symptoms can lead to costly repairs, as a compressor that works without proper lubrication or under low pressure quickly fails. Let’s look at the main scenarios of system failure.
Critical reduction of Freon levels
The most common reason why air-conditioner stops cooling the air, this is a banal leak of refrigerant. The air conditioning system is sealed, but over time, rubber seals dry up, and microcracks in the tubes allow the freon to gradually evaporate. It is normal to lose up to 10% of the refrigerant volume per year, but if the level drops faster, the system stops working efficiently.
At low levels. freon The pressure in the circuit drops and the low pressure sensor blocks the compressor from turning on to prevent it from breaking. That’s why you can hear a click when you turn on the A/C button, but the characteristic sound of the compressor will not start. In some cases, the compressor can be turned on for a few seconds and immediately turned off, which is a protective reaction of the system.
Leaks often occur at the connection points of aluminum tubes and rubber hoses, as well as through the cob shaft of the compressor. Visually notice the leakage of freon is impossible, since it is colorless and has no smell, but with it, compressor oil often comes out of the system, leaving fat spots on the aggregates under the hood. The detection of such traces is a sure sign of a leakage violation.
To restore efficiency, it is necessary to find the leak site, replace faulty elements and fill the system with new gas. Just “dilute” Freon without eliminating the cause is a temporary solution that will not solve the problem fundamentally. In addition, the ingress of moisture and air into the system when unqualified refueling can lead to the formation of acid, which corrodes the parts from the inside.
Failure of the compressor and its drive
The compressor is the heart of the air conditioning system, and if it does not work, then there will be no cold in the cabin. The reasons for the failure of the unit itself can be several: from the failure of the electromagnetic clutch to the mechanical destruction of the piston group. If you hear an extraneous noise, whistle or knock when you turn on the air conditioner, this is an alarm signal that requires immediate diagnosis.
The electromagnetic clutch is responsible for connecting the pulley, which is constantly rotating from the engine, with the shaft of the compressor itself. Over time, the surface of the disc clutch wears out, the gap increases, and the clutch becomes impossible. Also often burns the coil of the electromagnetic valve, because of which the magnetic field is not created, and the disk is not pressed.
- ⚙️ Wear of bearing The pulley of the compressor causes a characteristic howl or hum, which is intensified when the air conditioner is turned on.
- 💥 Compressor jamming leads to a break of the belt of the attachment equipment and can damage other engine units.
- 🔌 Breaking the slitz or a breakdown of the clamping plate makes it impossible to transfer torque.
⚠️ Attention: Operating a car with a faulty compressor or a broken belt can lead to engine overheating and loss of control, as often the same belt drives the power steering pump and generator.
In modern vehicles with climate control Diagnostics of the compressor is complicated by the presence of complex control systems. For example, in some models Toyota or BMW Variable performance compressors are used that do not have a classical electromagnetic coupling and are controlled directly through an electronic system. Diagnosis of such nodes requires special equipment and qualification.
Problems with the air conditioner radiator and fan
The air conditioner radiator (capacitor) is located in the front of the car, often in front of the main engine cooler. Its task is to cool the compressed freon, turning it from gas into liquid. If the condenser is clogged with down, dirt or insects, heat exchange is disrupted, pressure in the system rises, and the air conditioner ceases to work effectively or is turned off by an alarm.
Especially often problems arise in traffic jams or at low speeds, when there is no natural blowing and the fan. If cooler It is not turned on when the air conditioner is activated, the pressure in the system quickly reaches critical values. This can be caused by a burned fan motor, a malfunction of the relay or fuse.
| Symptoms. | Possible cause | Decision |
|---|---|---|
| The air conditioner only gets cold on the move. | The condenser fan is not working | Fan electrics check |
| The system often shuts down. | Radiator contamination | Washing and cleaning of the condenser |
| A whistling from under the hood | Belt slippage | Replacement or tension of the belt |
| Warm air from deflectors | Breaching of the seal | Leakage search and refueling |
Cleaning the air conditioner radiator is a procedure that can be done on your own, but with caution. A high-pressure sink can deform thin aluminum plates, which will finally disable the heat exchanger. It is better to use special chemicals to clean radiators or blow compressed air in the direction opposite to the movement of the car.
Clogging of the system and expansion valve
Inside the circuit circulates not only freon, but also a special compressor oil that lubricates rubbing parts. Over time, wear products, dirt or moisture can accumulate in the system. Moisture is particularly dangerous: at low temperatures, it freezes in narrow channels, forming an ice plug that blocks the circulation of the refrigerant.
Frequently (clogging) occurs in the area expansion-valve (TRV) or dehumidifier receiver. These elements are responsible for regulating the flow of freon and cleaning the system of moisture. If the filter-dryer saturated with moisture or clogged with decay products, the throughput of the system falls, and the air conditioner stops cooling. Symptoms may be frost on the tubes or uneven system operation.
To eliminate blockages, a complete dismantling of the system, washing with a special solvent and replacing the filter elements is required. Using inappropriate washing fluids can damage rubber seals or leave residues that mix with the new oil and disable the new compressor in a short time.
Electrical faults and sensors
The modern car is packed with electronics, and the air conditioning system is no exception. For its work, many pressure, temperature and position sensors of the valves are responsible. If electronic control (ECU) receives incorrect data or a signal from one of the sensors is missing, it may prohibit the compressor from turning on for safety reasons.
Often the culprit of the problems is the pressure sensor of Freon. It can fail on its own or due to oxidation of contacts in the connector. It is also worth checking the fuses responsible for the air conditioner chain. Their burnout usually indicates a short circuit in the circuit, for example, in the coil of the clutch or the fan motor.
- 🔋 Discharged battery Low voltage in the on-board network can block the work of energy-intensive consumers, including air conditioning.
- 🌡️ Evaporator temperature sensor It can mistakenly signal the radiator to freeze by turning off the compressor even if there is no ice.
- 🔌 Oxidation of contacts in connectors under the hood due to moisture and reagents disrupts the transmission of control signals.
⚠️ Attention: Attempts to “close” sensors or eliminate them from the circuit can lead to the system in emergency mode and the rapid failure of expensive equipment, such as a compressor.
Diagnostics of the electrical part require the use of a multimeter and a scanner that reads error codes from the climate control system. Without special equipment, it is almost impossible to find a circuit break or a faulty sensor, since visually the wires can look whole.
☑️ Primary diagnostics of electricians
Impact of recycling and valve regimes
Sometimes the problem lies not in the refrigeration unit itself, but in the air distribution system. If it works in the salon recycling For too long, the air may become stale and humidity will rise, which will reduce the efficiency of cooling. In addition, condensation can form on the flaps, which under certain conditions interferes with their normal course.
The mechanical flaps that control airflows can jam or break. In this case, cold air from the evaporator simply does not reach the deflectors, mixing with hot air from the stove or staying inside the torpedo. This is often accompanied by strange sounds from behind the glove compartment or under the instrument panel.
In cars with climate control Servo actuators (actuators) are responsible for the movement of the valve. If one of them fails, the system may not switch to cooling mode or blow only to the legs, ignoring the command to supply cold air to the face. Diagnostics of such malfunctions often requires removal of part of the instrument panel.
FAQ: Frequently Asked Questions
Why does the air conditioner start to get cold only in traffic?
The problem is probably the lack of capacitor. Check the cooling fan: it should be turned on forcibly when the air conditioner is activated. Also, the cause may be pollution of the radiator down, which interferes with heat exchange in the absence of incoming air flow.
Can I drive with an air conditioner that is not working?
You can drive, but it is not recommended to ignore the problem. If the leak occurred through the oede of the compressor, moisture and dirt can get inside the system, which will lead to corrosion from the inside and the need to replace the entire circuit, not only the oede.
How often should the air conditioner be refilled?
In a serviceable system, refueling is required no more than once every 2-3 years. If the gas is going away faster, there is a leak that needs to be found and fixed. Regular annual refueling "just in case" is not required and even harmful if it violates the proportions of oil and freon.
Why does the air conditioner drip water?
It's a normal physical process. When the air is cooled, the moisture contained in it condenses on the evaporator (like dew on the grass) and is excreted through a drainage tube. If water pours into the cabin, then drainage is clogged, and it needs to be cleaned.