What Causes Smoke and a Burning Smell from the Car Air Conditioner?
2 Answers
Smoke and a burning smell from the car air conditioner are likely caused by loose connections in the blower or speed control resistor circuit, leading to overheating and burning. Here are some related points to consider: 1. Clean promptly: Regularly clean the air conditioner vents. The vents are often overlooked but are the dirtiest and most in need of cleaning. Long-term neglect can breed bacteria and viruses, and in summer, it can reduce cooling efficiency and increase fuel consumption. 2. Maintain promptly: Regularly service the air conditioner condenser. The condenser's main function is to facilitate heat exchange in the air. If it becomes dirty or damaged, the cooling effect during summer use will be significantly reduced. 3. Replace promptly: Clean or replace the air filter regularly. The car air conditioner filter plays a crucial role in maintenance. If the filter becomes clogged and is not cleaned for a long time, it can lead to poor air quality. Prolonged neglect can result in the absorption of harmful exhaust gases, and in winter, heating can even produce toxic gases.
The last time I encountered this situation was during a long-distance drive when the air conditioning suddenly emitted white smoke with a pungent smell of burning plastic, which scared me into pulling over immediately. This is most likely caused by a burnt blower motor, located behind the glove compartment on the passenger side. If it runs at full load for a long time or has leaves stuck inside, the coils can overheat and burn the insulation. Another possibility is a short circuit in the air conditioning resistor or wiring—when the wire insulation melts, it can produce smoke. The most dangerous scenario is a clogged evaporator causing compressor overpressure; overheating pistons can directly burn the refrigerant oil, producing a smell similar to burning engine oil. Remember, the first response should be to turn off the AC, shut off the engine, and open the windows. While waiting for help, avoid touching any buttons, as DIY disassembly might trigger a secondary short circuit.
