A weak flow of cold air from the deflectors often indicates a critical decrease in the level of refrigerant in the system or mechanical damage to the compressor. If air-conditioner ceased to perform its function immediately after winter downtime, most likely, there was a natural leakage of freon through microcracks in the seals, which dried up without oil lubrication. Owners of cars notice that the temperature of the outgoing stream ceases to fall below 15-18 degrees Celsius even at maximum fan speeds. Ignoring this symptom can lead to the failure of expensive compressor because of the oil fasting, as the oil circulates with the gas.
The first thing you need to conduct a visual inspection of the space under the hood, paying special attention to the pipes and connections of pipelines. The presence of oily spots on the tubes air-conditioner or cooling radiator is a sure sign of depressurization of the circuit. Often the problem lies not in complex electronics, but in the banal clogging of the cabin air filter, which physically limits the passage of air through the evaporator. A dirty filter creates resistance, which is why even a serviceable system cannot supply enough cooled air to the cabin.
It is also worth paying attention to the operation of the electrical part, in particular, the integrity of the fuses and the switching relay of the compressor clutch. If, when the button is switched on, A/C There is no characteristic click and drop in engine speed, so the electrical signal does not reach the actuator. In modern cars, this is responsible for a complex system of pressure sensors, which blocks the start when there is not enough freon to protect the equipment. Self-diagnosis is possible only if you have basic knowledge of the device of the climate control unit and a minimum set of tools.
Critical effects of pollution on heat exchange
One of the most common reasons why air conditioning is bad is the contamination of heat exchangers, in particular the condenser and evaporator. The condenser, located in front of the main radiator of the engine, takes the entire blow from road dust, down and insects. When the radiator cells are clogged, the heat return process is disrupted, and the refrigerant does not have time to effectively transition from the gaseous state to the liquid. This leads to an increase in pressure in the system and a decrease in overall cooling performance.
Inside the cabin, similar processes occur with the evaporator, which is hidden behind plastic torpedo panels. Condensate mixed with dust settles on its ribs, which creates an ideal environment for the reproduction of bacteria and the formation of mold. This “coat” works as a thermal insulator, preventing heat exchange between cold tubes and purged air. As a result, the user feels only a weak cold, and an unpleasant musty smell appears in the cabin.
⚠️ Warning: Attempting to flush the condenser with a high pressure kercher can deform soft aluminum honeycombs, which will permanently disable the knot and require expensive replacement.
To diagnose the condition of the external radiator, it is not necessary to disassemble half of the car, it is enough to carefully examine it through the bumper grille. If a visual inspection shows a dense layer of dirt between the engine and air conditioner radiator, an urgent cleaning is required. Professional washing is carried out with the removal of the bumper or through special slits using chemistry that dissolves organic deposits. Regular prevention avoids overheating of the system and maintains efficiency of operation climate control over the years.
Carry out washing of the condenser with compressed air and water under low pressure every 20-30 thousand kilometers of run to maintain maximum efficiency.
Problems with refrigerant and compressor
When the system lacks a working body, the cooling efficiency drops proportionally to the degree of leakage. Freon. R134a more modern R1234yf It circulates in a closed circuit, and its quantity is strictly regulated by the manufacturer. With insufficient gas levels, the compressor begins to work with increased load, trying to compensate for the lack of pressure, but can not create the necessary temperature drop. In such cases, a low pressure sensor often works, which completely disables the compressor clutch, preventing it from working.
The compressor is the heart of the system, and any knocking, vibration or extraneous noise when turned on speaks of mechanical wear. The pulley bearing can jam and the internal pistons or plates wear out, which will cause the compression to fall. If the compressor drives oil into the system instead of compressing the gas, the air conditioner will blow warm or slightly cool air. Replacing this unit requires vacuuming the system and refueling with new oil, as the old one loses its properties.
- 🛑 Leakage of freon through the oil shaft of the compressor is a frequent problem on runs over 100,000 km.
- 🛑 The wear of the piston group leads to the impossibility of creating working pressure in the circuit.
- 🛑 The jamming of the coupling is often caused by oxidation of the contacts or a break in the supply chain.
- 🛑 The ingress of moisture into the system causes the formation of an acid that corrodes the internals of the compressor.
It is important to understand that simply refueling with Freon without finding and fixing a leak is a temporary measure. The gas will still go away after a while, and with it the oil, which will finish off the remaining resource of the unit. Quality repair involves finding the site of leakage using an ultraviolet additive in oil or a leak detector. Only after sealing the contour is vacuumed to remove moisture and air, and then refueling with a strictly standardized amount of refrigerant.
Failure of the electrical part and sensors
Modern cars are packed with electronics, and the air conditioning system is no exception, driven by complex algorithms. EBOU. Failure of any pressure or temperature sensor can cause the control unit to artificially limit the performance of the compressor or turn it off altogether. For example, if the evaporator temperature sensor “thinks” that it has already icy, it will ban the compressor from working, even if it is hot in the cabin. Diagnosis of such malfunctions is impossible without connecting the scanner to the diagnostic connector. OBD-II.
Special attention deserves a fan cooling radiator, which must be turned on when the air conditioner. If the fan does not turn because of a burned motor, a faulty relay or fuse, the pressure in the system will increase dramatically. At this point, an emergency valve or high pressure sensor comes into action, forcibly turning off the compressor to avoid an explosion of the main line. As a result, the air conditioner is turned on for a short time, then turned off, without having time to cool the air.
| Component | Symptom of malfunction | Implications for the system |
|---|---|---|
| Pressure sensor | Compressor not switching on | Lack of cooling |
| Fan relay | Engine and freon overheating | Emergency shutdown |
| Clutch safety | No response to the A/C button | Breaking the food chain |
| Evaporator sensor | Short work cycles | Ice or warm air |
Checking electrical circuits begins with a visual inspection of the wiring for rubbing and oxidation of contacts. Often the problem lies in the oxidized connector, where the moisture got, which creates a high transient resistance. The use of a multimeter allows you to ring the power chain of the clutch and fans, localizing the cliff. Electrical repair is often cheaper than repairing a mechanical part, but requires accuracy and knowledge of the circuitry of a particular car.
Effects of recycling and dampering regimes
Sometimes the reason for poor cooling lies not in the technical malfunction of the nodes, but in the improper operation of the ventilation system. Taking hot air from the street in extreme heat significantly reduces the efficiency of the air conditioner, as the system has to constantly cool a new volume of hot air. Switching to recycling mode allows you to run the already cooled air through the evaporator again, quickly reducing the temperature in the cabin to comfortable values.
The airflow mixing valve, controlled by the gearbox motor, can also be a source of problems. If the valve drive jammed or knocked the calibration, it may not completely block the hot air from the stove. As a result, the streams are mixed, and a warm jet blows from the deflectors, although the compressor works properly. Diagnostics of this node often require removal of a part of the torpedo for visual control of the operation of the valve mechanism.
⚠️ Warning: Long-term use of recycling mode in winter or rain can lead to fogging of the glass due to increased humidity in the cabin.
To check the work of the flaps, you need to listen to the characteristic sounds of their movement when switching the blowing modes. The absence of motor gearbox sounds may indicate a burnt drive or mechanical jamming of the valve itself. Some cars have service calibration of the valves through a diagnostic scanner, which allows you to restore their correct operation without disassembly. Regularly checking the mobility of the valves helps to avoid situations where the air conditioner blows, but does not cold.
How to extend the life of air conditioner in winter?
Turn on the air conditioner for 5-10 minutes once a month, even in winter. This is necessary for the circulation of oil and lubrication of the compressor coils, preventing their drying and subsequent leaks.
Diagnosis and search for Freon leaks
The search for leakage is a mandatory step in restoring the system's operability if a critical decrease in the level of refrigerant is detected. A simple visual check often fails to produce results, as the gas escapes through microscopic pores or hidden compounds. Specialists use the method of injecting nitrogen under high pressure, followed by immersion of the nodes in water or treatment with a soap solution to search for bubbles. This allows you to find even the most minor violations of tightness.
A more modern and accurate method is to use an ultraviolet dye that is added to the system oil. After a short operation of the air conditioner, the places of leaks begin to glow under the UV lamp in a bright green-yellow color. This method is effective for finding slow-going Freon that cannot be detected by other means. Electronic leak detectors are also used that respond to the concentration of refrigerant molecules in the air, which allows scanning hard-to-reach places.
- 🔍 Visual search for oil spots at the joints of tubes and aggregates.
- 🔍 Use of a UV lamp after adding a fluorescent additive to the oil.
- 🔍 Application of an electronic halogen flow detector for joint scanning.
- 🔍 Nitrogen system pressure to detect major depressurization.
After detection and elimination of leaks, the system vacuuming procedure is carried out within 30-40 minutes. This is necessary to remove not only air, but also water vapor, which, when in contact with Freon, form aggressive acid. The acid destroys the internal parts of the compressor and aluminum tubes, causing repeated breakdowns. Quality vacuuming ensures long and stable operation of the repaired air-conditioner.
Quality repair of the air conditioner is impossible without the search for leakage and vacuuming of the system, a simple refueling will only delay a serious breakdown.
Prevention and proper maintenance
To the question “why does the conder not get cold” does not arise in the middle of the summer heat, you need to adhere to a regular maintenance schedule. At least once a year, preferably in the spring, it is recommended to check the pressure in the system and the condition of the drive belt. A belt with cracks or weakened tension can slip, which is why the compressor will not develop full revs, reducing the cooling efficiency.
The cabin filter should be replaced every 10-15 thousand kilometers, since its overgrowth directly affects the performance of the system. It is also useful to carry out antibacterial treatment of the evaporator with special foam compounds that kill the fungus and eliminate odors. An integrated approach to maintenance allows you to maintain the efficiency of the climate control unit at the level of a new car.
Do not forget that a good air conditioner is not only comfort, but also safety, as it drains the air, preventing fogging of the glass. Watch the cleanliness of radiators, change the filters in time and listen to the work of the units. At the first sign of reduced efficiency, it is better to consult specialists for diagnosis than to wait for a complete system failure at the most inopportune moment.
☑️ Spring air conditioning check
Why does air conditioning start to get worse at idle speeds?
At idle speeds, the performance of the water pump and fans decreases, which can lead to insufficient cooling of the condenser. If the radiators are contaminated or the fan is not working well, the pressure in the system increases and the compressor can shut down at the emergency threshold. Also, at low revs, the performance of the compressor itself may not be enough if it has wear.
Can I drive with an air conditioner that is not working?
You can drive, but if the cause is a leak, air and moisture could get into the system, which causes corrosion from the inside. In addition, the compressor can jam, which will cause the drive belt to break and stop the engine or generator on the go. It is better not to delay the diagnosis, even if you are willing to tolerate the heat.
How often should I fill the air conditioner with Freon?
A proper air conditioning system is completely sealed and does not require regular refueling. Natural loss is about 5-10% per year, so refueling may be required once every 2-3 years. If refueling is needed more often, then there is a leak in the system that needs to be fixed.
Is it harmful to turn on the air conditioner at full capacity?
A sharp start with maximum load creates stress for the compressor and the electric network of the car. It is recommended to first lower the windows, ventilate the cabin, start the engine, and only then turn on the air conditioner at medium speeds, gradually increasing power. This will extend the life of the units.