What Causes the High-Pressure Needle of a Car Air Conditioner to Swing Back and Forth?
2 Answers
The reasons for the high-pressure needle of a car air conditioner swinging back and forth are as follows: 1. Excessive pressure: The pressure inside the system is too high, causing the safety valve to release water. The solution is to reduce the pressure within the system. 2. Safety valve failure to close: The safety valve does not close completely. The solution is to close the safety valve properly. 3. Water leakage: Leakage caused by dirty water quality, blockages, or damage. The solution is to replace the water used. Precautions for using a car air conditioner are as follows: 1. Note 1: When using the car air conditioner, choose an appropriate temperature setting. Setting the temperature too low can affect health, so the temperature inside the car should be maintained between 18°C and 25°C. Excessively low temperatures can easily make people sick. 2. Note 2: Before entering the car in summer, open the windows for ventilation and turn on the external circulation to expel the hot air. Do not smoke in the car with the air conditioner on, as the smoke cannot be quickly expelled, irritating the eyes and respiratory system, which is harmful to health. If smoking, adjust the air conditioner ventilation control to the "exhaust" position to expel the smoke from the car. 3. Note 3: Running the air conditioner for long periods can cause wear and tear on the cooling system, as the air conditioner is a heavy load on the engine, which itself is a heat source. Especially in hot weather, some small-displacement cars may even experience boiling water, affecting driving and reducing air conditioner efficiency.
I have encountered the issue of the air conditioning high-pressure gauge needle swinging back and forth, which usually indicates unstable internal system pressure, affecting the cooling performance. The most common causes are insufficient refrigerant or a leak leading to pressure imbalance; a faulty expansion valve, such as being stuck and not properly regulating the refrigerant flow, or air/moisture contamination in the system causing erratic movement during compression. A dirty condenser obstructing heat dissipation can also cause this. I must remind you that such fluctuations may damage the compressor and shorten its lifespan—promptly checking refrigerant levels and valve functionality is crucial. For DIY checks, inspect pipe joints for oil stains as leakage signs, but it's best to visit a service center for instrument-based pressure testing to prevent further issues.
