What Causes a Burning Smell When the Car Air Conditioner is On?

[OMason]

There are several reasons why a burning smell may occur when the car air conditioner is running: 1. If the smell is not like burning plastic, it could be due to dust on the heating pipe being roasted when the electric auxiliary heating is in use. This smell usually fades after a few uses. It is recommended to turn off the electric auxiliary heating and have an air conditioner technician clean the dust on and around the heating pipe. 2. If the smell resembles burning plastic, it might be caused by a blocked air vent, leading to heat buildup and melting of internal plastic components. First, check if the air vent is obstructed by testing the airflow with your hand. If the airflow is weak, it is advisable to open the air conditioner for inspection and remove any blockages. 3. The issue could also stem from aging wiring or abnormal heating elements in the air conditioner, causing excessive heat production. In this case, the air conditioner should be opened for inspection.