Negative pressure weather

There may be two reasons why the air conditioner has high pressure and no low pressure. First, the system refrigerant leaks, showing high pressure but not high, low pressure or negative pressure. Second, the capillary or filter of the system is blocked, which is characterized by very high pressure and negative pressure.

fault diagnosis

Using pressure gauge to check the faults of automobile air conditioning and refrigeration system can generally be divided into two States: compressor shutdown and operation.

The compressor stops running.

After the compressor stops running for more than 10 hour, the high pressure side and the low pressure side of the compressor should have the same value. If the values displayed by the high and low meters are not equal, the system is blocked, and the expansion valve, liquid storage tank and pipeline should be checked.

Compressor operation

When the compressor is running, control the engine speed at 1500 ~ 2000 r/min, and start the air conditioner to make the compressor work. Under normal circumstances, the low pressure side pressure is about 150 ~ 250 kPa, and the high pressure side pressure is about 1400 ~ 1600 kPa.

Blockage check

If the indication of the pressure gauge is inconsistent with the normal value, the following methods can be used for fault diagnosis.