What is the analysis approach for car air conditioning malfunctions?

[RoseAnn]

Car air conditioning malfunction analysis follows a three-step approach: look, listen, and touch. Below are the relevant details: 1. If bubbles continuously flow out in the sight glass, with the refrigerant appearing to flutter, it indicates very little refrigerant in the system. In this case, there is almost no temperature difference between the high-pressure and low-pressure sides. If occasional bubbles appear at intervals of 1-2 seconds, it indicates insufficient refrigerant in the system. At this time, the high-pressure side is warm, while the low-pressure side is slightly cool. 2. Listen for any abnormal noises or knocking sounds when the compressor is running; their presence indicates a problem. Also, check for any abnormal noises from the evaporator blower, condenser fan, or motor operation. 3. Touch the high-pressure and low-pressure pipes of the refrigeration system. It is normal for the high-pressure pipe to be hot to the touch and the low-pressure pipe to be cold or icy. Additionally, it is normal to feel a cold sensation from the air blown out of the air conditioning vents when touched by hand.