Should You Turn Off the Air Conditioning Before Turning Off the Car?

[SanJasper]

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.

[SanMila]

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.

[LeAshlyn]

I've been driving for over a decade and always think about saving money and fuel. So I make sure to turn off the air conditioning before shutting down the engine. Starting the car with the AC on immediately consumes extra gasoline, and over time, fuel costs add up. Additionally, it puts more strain on the battery, leading to more frequent replacements, which is costly. Although it's tempting to leave it on during hot weather, the high load during startup can also damage electrical components, such as blowing fuses or relays, and repairs aren't cheap. I've tested it: turning off the AC before starting the engine makes it run smoother, and on average, it saves a bit of fuel per 100 kilometers, adding up to hundreds of dollars a year. Even if it gets uncomfortably hot without the AC, rolling down the windows for a bit after turning it off before shutting down the engine helps transition—practical and cost-effective.

[ClaireDella]

Hey, I usually don't pay much attention to this small action. Modern car designs are advanced, and leaving the AC on when turning off the engine isn't a big deal—the system automatically controls the load to prevent easy malfunctions. But turning it off is even better—it prevents battery stress during startup and avoids odor buildup. In summer, the car often gets damp. After forgetting to turn it off a few times, my car smelled musty, and I had to replace the AC filter. Overall, developing the habit of turning off the AC before shutting down the engine is more worry-free, protecting the car and reducing hassles. It's simple to operate—just push a button, no hassle.

[ChloeDella]

I believe turning off the AC is crucial for battery protection and reducing unexpected issues. During startup, multiple electrical devices running simultaneously can impact the battery, especially in older vehicles or during frequent short trips, which may lead to premature battery failure and affect other electronic devices like lights or audio systems. Additionally, residual moisture inside the AC system can cause mold or odors if left unchecked for long periods, impacting cabin air quality. Once during winter, I neglected this, and my battery failed within weeks. After repairs, I developed the habit of never making that mistake again. I recommend turning off the AC a minute or two before shutting down the engine to allow air circulation, a simple step to prevent major troubles.