Fact or Myth

[Jamesmaier]

I've always been told that before i turn off my car its best to turn off the heater/air con. I was just wondering why this is the case and if it actually does make a difference......

[MR_VX]

id like to know as well. my misses does it all the time. it shits me

[tommySV6Ute]

Plenty of google results, one here: I Heart Change: The car air conditioning debate

I thought it removed the load on the engine on restart if you turned the aircon off..

Every site you visit has a different opinion.

[soop]

The AC compressor wont engage untill the car has started anyway.
If your battery is knackered it might help with the voltage. Car needs minimum of 12volts to fire.

[Rhin0o8]

everything gets turnt off before i turn the car off.

A/C, Radio, Lights.. even the power windows go up before i turn the engine off
also turn off the rear demister in the winter
Habit i guess

But i will save drain on the battery on the next start-up

[Rhin0o8]

How about running the A/C without the Fan on 1,2,3, high etc

Im pretty sure you need the fan on atleast 1 or the A/C compressor will burn out?

[tommySV6Ute]

If the fan is off the aircon/compressor will be off.

[Jamesmaier]

ive heard because it decompresses the compressor when you turn if off before you turn the car off. and if your going to get back into your car 5 minutes later you dont want the compressor fully loaded.

[GothicKidd]

My mum always turns everything off, I pre much just jump out my car.. I have a cool feature for my headlights tho, If I turn my headlights while the ignition is on and turn the key off or w/e.. when I open the door the lights while turn off till I go to start my car again. - Yeah I start my car with my headlights on.. even Highbeam sometimes.. Its a slower start then normal but idc :P
The AC compressor would cause Load making it harder to start
I wasnt sure what caused it, but I do think after time you could blow your Engine fuse.. Maybe

[Brett_jjj]

Im not sure if the ECU cuts the A/C compressor off at startup.I know it shuts it off once certain revs are reached,or if a certain load is put on the engine,but not sure about startup though.I might have to check that out.I always make sure its off before I start the car anyway.Same with the headlights.
EDIT: Just went out and checked it out.The ECU cuts the compressor off anyway at startup.The compressor comes on a couple of seconds after the engine is running,so there ya go,starting the engine with the A/C on wont matter or hurt anything.

[edals]

I Just switch it all off, Just force of habit, And when i get back into the car everything is ready to be set up again. I dont know about the AC thing, I guess it cant hurt though? making it dis-engage first.

[caaf]

The only reason I can think that (and I do it) the AC should be turned off a minute or so prior as it slows down/stop the process of bacteria forming on the AC coil in the car. Heater and fan.. That stuff can stay on (Mine constantly on "2" for positive pressure in the cabin.