Can the Air Conditioner Still Work When the Engine is Off?

[SanAva]

No, it cannot. Here are the relevant explanations: 1. The air conditioner automatically turns off when the engine is shut down: The car's air conditioner will automatically turn off after the engine is shut down. This is because the air conditioner is driven by the engine, and when the engine is off, the air conditioner stops working. 2. Tips for using the car air conditioner: It is best to turn off the A/C button one or two minutes before parking and shutting off the engine. This allows the blower to dry the water vapor in the air vents and pipes, preventing bacterial growth inside the air conditioner and reducing the occurrence of odors. Additionally, if the air conditioner is not turned off before shutting down the engine, the next time the vehicle is started, the engine will have to start with the load of the air conditioner. The best practice is to wait two or three minutes after starting the vehicle, allowing the engine to be fully lubricated, before using the air conditioner.

[MorganDella]

Well, I often tinker with my car myself, and I understand that the air conditioning system mainly relies on the engine running to drive the compressor via a belt. Once the engine is turned off, the compressor stops, and the air conditioning cooling function immediately fails, leaving only the fan blowing air—but this is a battery-powered fan, not actual cold air. For short stops, the fan can still run for a while, but prolonged use will drain the battery, potentially leading to a dead battery and difficulty starting the car. I recommend keeping the engine running while parked and waiting, so the air conditioning functions normally and avoids awkward situations or issues. During regular vehicle maintenance, also check the belt and compressor condition to reduce unexpected failures. Although summer heat can be unbearable, safety comes first—don’t turn off the engine just to save fuel and misuse the air conditioning.

[VanEmery]

Haha, as a driver, I once tried turning off the engine to cool down with the AC while driving my kids around. I noticed the fan could still blow some air for a few seconds, but it wasn't cold—just like room temperature air, and the car quickly heated up. With the engine off, the compressor doesn't work, so the AC can't provide any cooling at all. Doing this for too long drains the battery fast, and if it dies, you're in trouble. So now I’ve gotten used to keeping the engine running when parked to keep the AC cool. Especially in traffic jams, keeping the engine on is both comfortable and hassle-free. Proper vehicle electrical maintenance also helps prevent unexpected issues.

[LeMaria]

From the perspective of experiencing an electric vehicle, the air conditioning can still function when the engine is off because the pure electric power supply operates independently. However, I understand that in conventional fuel-powered vehicles, the compressor completely shuts down after the engine is turned off, rendering the air conditioning ineffective. The fan, powered by the battery, can only operate for a short period and is not recommended for prolonged use. Ensure the vehicle is well-maintained to avoid battery depletion issues.

[LaEvelyn]

For safety reasons, attempting to cool with the air conditioning after the engine is turned off is impractical, as the compressor stops functioning. Brief operation of the fan consumes significant power, potentially causing starting difficulties. It is recommended to use the air conditioning only when the engine is running to ensure reliability and comfort. Regularly check the vehicle's battery and maintain the air conditioning system.