Why does the high-pressure gauge needle of a car air conditioner swing back and forth?
2 Answers
There are several reasons why the high-pressure gauge needle of a car air conditioner swings back and forth: 1. The system pressure is too high, causing the safety valve to release water. The system pressure can be reduced. 2. The safety valve is not completely closed. The safety valve can be closed. 3. The water quality is too dirty, causing blockages or damage, leading to leaks. The water used can be replaced. Here is some additional information: 1. If you find that the air conditioner is not cooling well, the airflow is weak, or it is not cooling at all, you need to check whether each component is functioning properly and whether there is a lack of refrigerant. The refrigerant must be added according to the model specified in the vehicle manual. 2. The air filter should be replaced regularly. In urban driving conditions, the air filter should be replaced every 3,000 kilometers. This not only keeps the intake system cleaner but also prevents a decrease in cooling capacity due to a clogged air filter.
My AC high-pressure gauge keeps fluctuating, which is really annoying. The common causes are insufficient refrigerant (what we call Freon) or uneven distribution, leading to unstable pressure fluctuations. It could also be due to wear and tear on the compressor clutch, causing it to stick during start-stop intervals and trigger oscillations. Air or moisture in the system can also cause this issue, especially during heavy summer usage. From my experience, don’t delay getting it checked—otherwise, the compressor might burn out, leading to costly repairs. I recommend regular checks of refrigerant levels and cleaning the radiator, like a simple maintenance before spring and summer as a precaution. If you notice a problem, park safely first and check for unusual engine noises or leaks—safety always comes first.
