The condition of the climate system is one of the key factors when buying a used car. Often, the repair of this unit costs at least 15,000 rubles, for this reason, a full check before the transaction becomes a mandatory procedure.
Checking the operation of the compressor under the hood
Diagnostics begin with starting the engine and warming it up to operating temperature. After that, turn on the air conditioner and set the minimum temperature value in the cabin. Then attention is focused on the engine compartment and the operation of the corresponding units.
A working compressor, when the system is turned on, gives a characteristic click - this is one of the basic signs of its functioning. On most modern foreign cars at the same time, especially when parking, additional radiator fans start to work.
During a visual inspection, you can see that the compressor pulley rotates constantly, but this does not mean that the system is active. The actual start occurs when the pressure plate is attracted to the pulley - it is this moment that indicates the beginning of refrigerant circulation.
Assessment of efficiency by air temperature
The main criterion for the serviceability of the air conditioner is the ability to actually cool the air. For accurate data, it is recommended to use an electronic thermometer, since subjective sensations do not give an objective picture.
The procedure for checking is as follows:
- the thermometer probe is placed inside the duct deflector;
- the system is switched to maximum cooling mode;
- the fan speed is set to maximum.
How to determine the proper operation of the system
The measurement results allow us to draw an unambiguous conclusion about the condition of the climate system. With an air temperature in the cabin of about +20 °C, a working air conditioner should provide a temperature reduction at the outlet of the deflector by at least 10 degrees.
If this condition is met, we can talk about the correct filling of the system and the normal pressure level corresponding to the factory parameters.
Otherwise, the following problems are possible:
- refrigerant leak;
- compressor wear;
- contamination of cooling system radiators.
The absence of pronounced cooling or a slight temperature difference indicates a malfunction, the elimination of which may require investments of tens of thousands of rubles.