Does turning off the car directly without turning off the air conditioning affect the vehicle?

[BentleyLee]

Turning off the engine without turning off the air conditioning does affect the car, as it increases the load on the motor, damages the engine, and promotes bacterial growth. Here are some additional details: Components of the air conditioning system: Compressor, electronically controlled clutch, condenser evaporator, expansion valve, receiver-drier, pipelines, condenser fan, vacuum solenoid valve, idle speed controller, and control system. The functions of the air conditioning system are: Adjusting the interior temperature, filtering the air entering the cabin; absorbing moisture from the air; maintaining clean air to prevent bacterial growth. Air conditioning maintenance methods: Timely addition of refrigerant; regular replacement of filters; using ozone for sterilization.

[StJaxson]

I've been driving for twenty years and often forget to turn off the AC before shutting down the engine. Actually, doing it once or twice occasionally is completely fine, but making it a habit can affect the battery's lifespan. During the next startup, both the engine and the AC compressor work simultaneously, putting an instant heavy load on the battery. Last week, when I helped my neighbor measure his old car, we found that this practice caused a 30% drop in battery voltage. Over time, this can wear out the starter and cause wiring to overheat. It's advisable to develop the habit of turning off the AC 30 seconds before shutting down the engine, especially in winter when the defogging mode consumes even more power. Now, before parking, I turn off the AC button first and let the fan blow natural air for a while, which not only protects the circuit but also saves fuel.

[ChristianAnn]

Our family SUV has covered 80,000 kilometers in five years. My husband used to always forget to turn off the AC before shutting down the engine. Last year, the battery suddenly died, and the mechanic said it was caused by this habit. The moment you start the car consumes the most electricity, and if the AC compressor kicks in at the same time, it’s like making the battery do two heavy tasks simultaneously—just like asking someone to carry sacks right after waking up, which is really hard on the body. After we broke the habit, the battery lasted three years without needing replacement. Remember this: in winter, heating is harder on the electrical system than cooling because it requires activating the heating element. Next time, turn off the AC before reaching your destination to let the fan dry out the ducts, which also helps prevent musty odors.

[LeDerek]

I've seen too many problems caused by not turning off the AC during car repairs. The most typical one is the starter making strange noises, like sand stuck in the gears. The principle is simple: when the engine is turned off, there's pressure in the AC pipes, and starting the engine directly will make the compressor start under load. Last week, a BMW owner spent 2000 yuan replacing the starter, all because of this habit over three years. Actually, the solution is very simple: turn off the AC button before reaching your destination and use the external circulation to blow air; or install a voltage protector. New cars now have a delayed power-off function, but older cars need special attention. Developing good habits saves much more money than repairs.