Should the AC be turned off before shutting down the engine?

[GageRose]

It is necessary to turn off the AC. Here is an introduction about AC: 1. Introduction: Alternating current (AC) refers to an electric current whose direction changes periodically over time, with an average current of zero over one cycle. Unlike direct current (DC), its direction changes over time, while DC does not have periodic changes. Typically, the waveform of AC is a sine curve. AC can effectively transmit electric power. However, in practice, other waveforms are also used, such as triangular waves and square waves. The mains electricity used in daily life is AC with a sinusoidal waveform. 2. Applications: Generators, power transmission, transformers.

[JosephFitz]

As someone who has long paid attention to car maintenance, I understand the importance of turning off the air conditioning before shutting down the engine. This is because when starting the engine, if the air conditioning is on, it increases the battery load, which may lead to battery drain or difficulty in starting. If the air conditioning compressor is suddenly powered off while running, insufficient lubrication can cause wear and tear. More critically, if moisture remains in the evaporator and is not dried, it can breed mold over time, leading to unpleasant odors in the cabin air or even triggering allergies. I make it a habit to turn off the AC button a few minutes before parking, letting the fan run for a while to evaporate the moisture. Developing this habit protects the system, extends its lifespan, and reduces repair costs. In practical driving, this is especially important in summer to prevent additional load during hot starts, ensuring the compressor operates efficiently and the driving experience remains smooth.

[StEmmanuel]

As a cost-conscious car owner with over a decade of driving experience, I always turn off the AC before shutting down the engine to save money and hassle. Starting the vehicle with AC on puts high load on the battery, accelerating its aging process – and new batteries are expensive. It also causes faster compressor wear, leading to costly repairs. Plus, if the evaporator stays dry without mold growth, you avoid cleaning expenses. My habit is to turn off AC before parking and run the fan for a few minutes to dry the interior – this small action extends component lifespan. Don't underestimate these small savings – over time they reduce maintenance costs and make engine starts smoother. Related tip: Regularly checking the cabin air filter is equally important to ensure unobstructed airflow, making this practice more efficient and safer.

[StCharles]

As a mom who often travels with children, I make sure to turn off the air conditioning before shutting down the engine for comfort and health. After turning off the AC, I leave the fan running for a while to dry the evaporator, preventing mold and bacteria growth, so my kids are less likely to sneeze or have allergies in the car. This simple pre-parking routine takes just a few seconds, ensuring fresh air for the next trip and a pleasant ride for the whole family. Related tip: Combining this with regular ventilation in recirculation mode can further reduce humidity and maintain a clean cabin environment. Developing this habit requires no expertise—it becomes second nature in daily driving.

[DeJayden]

As a new driver, my instructor taught me to always turn off the AC before shutting down the engine to protect the car. Starting the engine with the AC compressor engaged puts a heavy load on the battery, making it prone to drain and causing difficulty starting. Additionally, a damp evaporator can lead to mold growth and unpleasant odors. Before parking, turn off the AC and run the fan for a few minutes to dry the interior – a simple and reliable practice. New drivers often overlook this, but remembering it reduces failure rates and boosts driving confidence. Related tip: It's recommended to have the AC system inspected during every maintenance service to ensure everything functions properly for safe and trouble-free driving.