Should You Turn Off the Air Conditioning Before Turning Off the Car?
2 Answers
You should turn off the air conditioning before turning off the car for the following reasons: 1. If you don't turn off the air conditioning before shutting down the engine, the starter motor will have to handle both the engine and the air conditioning system during the next startup, increasing the load and potentially damaging the vehicle. 2. Turning off the engine without first turning off the air conditioning can cause water vapor to condense on the evaporator, leading to bacterial growth and unpleasant odors in the air conditioning system. It is recommended to turn off the air conditioning before shutting down the engine and wait for two to three minutes after starting the car to allow the engine to be properly lubricated before turning on the air conditioning again. During the break-in period of a car, the power supply system, including the motor and battery, may not be very stable, and failing to turn off the air conditioning can indeed lead to faults due to excessive voltage.
I've always believed that turning off the air conditioning before shutting down the engine is a good habit, especially when it comes to long-term car maintenance. If you don't turn off the AC before shutting down, it will automatically turn on the next time you start the car, which instantly increases the load on the engine. This might affect the smoothness of startup and could even shorten the battery's lifespan, especially in cold weather or when the car's battery is already old. What's more troublesome is that residual moisture in the AC system can easily breed mold, leading to strange odors in the car after a few days, which are difficult to clean. I learned this the hard way—once I shut down without turning off the AC, and the next day, the car made a loud buzzing noise when starting. The mechanic said the compressor could be damaged. Although newer cars have protective measures, turning off the AC a few seconds early can prevent these issues, ensuring the car lasts longer with fewer problems and saving on repair costs. Developing this small habit is definitely worth it.
