What happens when a car pressure switch fails?
2 Answers
The symptoms of a failed car air conditioning pressure switch are: poor contact of the contacts or abnormal operation of the pressure switch, resulting in the compressor not working and failing to provide normal pressure protection. The car air conditioning pressure switch is an essential control component to ensure the normal operation of the car air conditioning refrigeration system. According to pressure control, it can be divided into high, medium, and low pressure; the wiring can be 2, 3, or 4 wires. The high and low pressure switches control the start and stop of the compressor when abnormal pressure occurs in the system. The following is an introduction to the content: 1. The control range of the high pressure switch is generally between 15-26 bar; 2. The low pressure switch is generally between 0-4 bar; 3. The medium pressure switch is generally 17 bar.
I remember driving for over 20 years, and during a recent trip, it was extremely hot when suddenly the air conditioning stopped cooling. The car became as stuffy as a steamer. After checking, I found out the pressure switch was broken, so the compressor wouldn't work at all, and the refrigerant couldn't circulate—no cold air whatsoever. What's more annoying is that a faulty switch can sometimes falsely trigger the system's protection, causing the engine warning light to come on. On the highway, I had to roll down the windows for ventilation, which significantly increased fuel consumption, and the gas tank emptied much faster. I hurried to the repair shop to replace the switch, and the mechanic said parts like these in older cars tend to wear out easily. He recommended annual maintenance for the AC system to prevent similar issues. That experience taught me a lesson—I now keep an emergency fan in the car for unexpected situations, or else long trips would be miserable.
