Do I really have to shut off the ac in the car?
September 20, 2008 4:17 AM Subscribe
My girlfriend swears that you have to shut off the AC and then the fan and then the car. Otherwise, you kill the battery AND hurt the AC. Is any of this true?
posted by smersh to travel & transportation (31 answers total)
I'm currently living in India, driving a car that has a non-digital A/C unit. According to my girlfriend (and her father, and her mechanic (supposedly)), you have to shut off the A/C first, and then you turn off the fan BEFORE turning off the car. If you don't, the theory goes, you kill the battery and the A/C compressor (or some other A/C component).
Now, since this is an analog A/C unit (meaning you can turn the knob and press the button even when the car is off), doesn't that really mean I can turn off the car and then turn off the fan and a/c after the fact?
I've really thought the whole point was to not put extra strain on the battery when starting the car. I didn't think it had to do with anything else. But, I promised her I'd ask metafilter to get a definitive answer.
So, here's what I need to know:
1) can it hurt the car in any way to turn off the fan, a/c, and car in the "wrong" order?
2) if so, what would it hurt, and how?
3) if it doesn't hurt anything anymore, did it ever? In other words, if it doesn't exist now, is there a historical basis to this? Or is it pure superstition?
I really appreciate any insight.