What are the symptoms of a faulty car air conditioning temperature control switch?
3 Answers
Symptoms of a faulty car air conditioning temperature control switch: 1. Intermittent cooling of the car air conditioning; 2. No cooling in the car air conditioning. The repair method involves identifying the leakage point, replacing the failed components, then performing vacuuming, pressure testing, and refilling the refrigerant according to the specified amount for the air conditioning system to resolve the issue. The temperature control switch regulates the fan operation. When the water temperature reaches around 88 degrees, the temperature control switch controls the fan to run at a low speed. At 100 degrees or above, the fan runs at high speed. The temperature control switch is usually installed on the radiator or near the water pipe leading to the engine cylinder head and has three wires. Only electronic temperature control switches have three wires: one is the negative terminal from the switch, one connects to the dryer bottle to protect the air conditioning system, and the other is the power supply.
While driving, my car's air conditioning temperature control switch broke, and it felt like my luck was tied up. When pressing the temperature knob or button, it either got stuck or jumped around, causing the air temperature to go completely haywire. In summer, when it should have been cool, hot air blew out, making me sweat profusely; in winter, when I wanted warmth, cold air blasted out, leaving me shivering. It was pure misery on the road, especially on the highway, where distracted adjustments nearly caused an accident. That time, I thought it was an issue with the AC compressor, but after inspection, it turned out the switch's internal contacts were severely worn, leading to poor contact and loss of control. I recommend regularly using a hairdryer to clean the gaps around the buttons to prevent dust buildup or oxidation, which can affect sensitivity. Regular maintenance can also nip problems in the bud. If it breaks, get that small part replaced at a repair shop immediately to avoid further trouble and safety risks. Remember, don’t let temperature adjustments distract you while driving!
When the air conditioning temperature control switch malfunctions, it behaves erratically. It's supposed to precisely regulate the cabin temperature, but acts like a temperamental child—the knob rotation yields no response, display data jumps randomly, or the vent output fluctuates wildly between extreme cold and heat, completely failing to maintain the set value. I often suspect this is caused by aging internal components or short-circuited wiring leading to failed thermosensitive control, which is more common in automatic climate control systems. After prolonged use, buttons may stick or fail entirely—for instance, pressing AUTO mode doesn't trigger automatic regulation, and manual override performs unreliably. Such issues not only compromise comfort but also increase power consumption. Start with basic checks: turn the AC off and restart to test responsiveness. If that fails, inspect fuses or wiring connections. Maintaining good cabin ventilation slows switch wear, while preventing grease corrosion on contacts helps detect problems early for hassle-free maintenance.
