What is the reason for the intermittent illumination of the car AC light?
2 Answers
Car AC light intermittent illumination may be caused by the following reasons: 1. Sensor damage: The sensor is damaged and needs to be replaced. 2. Compressor burnout: Check if the motor coil is burned out, and finally inspect the starter condition. Sometimes the overheating protector is activated, requiring a certain time for the compressor temperature to drop before restarting. 3. Thermostat failure: The thermostat cannot reset due to sintered contacts that prevent disengagement, causing malfunction. 4. Compressor wiring: Incorrect wiring of compressor coil circuits requires line inspection.
I've encountered this situation before, usually due to poor contact in the buttons of the AC control panel. Those tiny switches wear out over time, especially for owners who frequently use the AC button. Loose wiring connections are also common culprits, particularly when the contact becomes intermittent during bumpy rides. There's also a less-known possibility – unstable system voltage. A slipping alternator belt can cause voltage fluctuations, making the AC light flicker erratically. I suggest you try repeatedly pressing the switch when parked; if the light dims and brightens with each press, it's most likely a contact issue. I remember my friend's car had this exact problem last time – upon opening the panel, we found the wiring harness connectors were oxidized, and a spray of electronic cleaner fixed it. Of course, poor contact in the fuse holder could also be the troublemaker.
