Should the AUTO Air Conditioning Be Turned Off Before Shutting Down the Engine?
4 Answers
It is necessary to turn off the AUTO air conditioning before shutting down the engine. Here are the related explanations: 1. Increased load: If the air conditioning is not turned off before shutting down the engine, the evaporator, which has been cooling continuously, will have a relatively low temperature after parking and will adsorb many small water droplets on its surface. If left unattended, bacteria will breed inside the evaporator over time, producing a musty odor. 2. Impact on lifespan: If the air conditioning is not turned off before shutting down the engine, it will automatically turn on when the engine is started next time, which unnecessarily increases the load on the engine and damages it. 3. Correct procedure: The proper operation should be to turn off the air conditioning first, then switch to the external circulation mode to allow the blower to dry the water droplets on the evaporator before locking the car.
I've been using cars with automatic air conditioning for a long time, and I've never manually turned it off before shutting down the engine because the AC automatically stops working when I turn off the engine. This was considered in the vehicle design, such as cutting off the power instantly when shutting down to protect the battery from excessive discharge, making it worry-free and convenient. I've driven several models myself, including SUVs and sedans, all operated this way, and haven't had any issues in three years. If you're unsure, you can wait a few seconds after starting the engine before turning on the AC to give the electrical system a buffer; or check the battery health and small circuits during regular maintenance. An extra tip: setting the AC to around 25 degrees is the most energy-efficient and comfortable, avoid setting it too low or too high. In short, modern technology makes driving easier, so why add unnecessary burdens?
Having driven for over twenty years, experience tells me that there's no need to specifically turn off the AUTO air conditioning before shutting down the engine. Once the engine stops, the entire vehicle's electrical system cuts off simultaneously, and the air conditioning naturally turns off. This design prevents high-load impacts on the battery or relay damage. I've seen many owners forget about this, and their cars remain perfectly fine. Risks only arise when the battery is old or during extremely cold weather. It's advisable to wait for the RPM to stabilize after starting the engine before turning on the air conditioning to reduce instantaneous current fluctuations. For maintenance, focus more on the battery's lifespan and the condition of the wiring, checking the voltage monthly is sufficient. Don't get bogged down by complicated theories; the essence is to enjoy the convenience of simple driving.
As someone with some knowledge of automotive electronics, I would say the AUTO air conditioning automatically turns off when the engine is shut down, so there's no need to manually switch it off. After turning off the ignition switch, the controller will cut off the power supply to protect the battery and circuits from damage. Even if the air conditioning is left on when shutting down, the system relay can handle instantaneous load changes. Occasionally, corroded wiring may cause issues, but in most cases, it's not a problem. I usually pay attention to checking wire connections and filter cleanliness. In short, the design is intelligent, so users don't need to worry too much.
