Turn off A/C before shutting off engine?
#1
Racer
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Turn off A/C before shutting off engine?
Well, A/C is not a valid search term...and, searching 'Conditioning' posts brings up mostly trouble shooting posts...
For some reason, I have it in my head, that it is better for the 993 to shut off the A/C before shutting off the car? I know that most other cars on the planet today, with auto climate controls, do not require, or even recommend this turning off the a/c before shutting off the engine...
Any issues with simply leaving the A/C on (small snowflake button pressed in), always!
In winter (well, never really that cold here in Ca), when the weather cools or of course rainy days, having the A/C on dries the air in the car, preventing fog up.
Thanks all...
For some reason, I have it in my head, that it is better for the 993 to shut off the A/C before shutting off the car? I know that most other cars on the planet today, with auto climate controls, do not require, or even recommend this turning off the a/c before shutting off the engine...
Any issues with simply leaving the A/C on (small snowflake button pressed in), always!
In winter (well, never really that cold here in Ca), when the weather cools or of course rainy days, having the A/C on dries the air in the car, preventing fog up.
Thanks all...
#2
Three Wheelin'
I turn EVERYTHING off, before I exit the car. (I even have the interior lights set to 'permanently off' on both doors). The only thing that stays (temporarily) on - is the climate control unit - which, eventually, switches itself off -- and, of course, the immobilizer, which I flick to 'on' as I maneuver to close the garage door. Net result - the only thing that's ever ON, when I'm not in the car, is the immobilizer.
G.
P.S. As one who flies, we are taught, from day one, to have *all electrical items set to OFF*, before starting the engine(s). In this way any 'spurious' voltages do NOT go to 'the electrics' (radios, transponder, etc.) during engine start. If I owned my own plane, I could be assured of this, but since I rent there's no guarantee that the previous 'renter' followed the checklist. Still, the basic point is 'the next time you start' that nothing electronic should be 'on'.
G.
P.S. As one who flies, we are taught, from day one, to have *all electrical items set to OFF*, before starting the engine(s). In this way any 'spurious' voltages do NOT go to 'the electrics' (radios, transponder, etc.) during engine start. If I owned my own plane, I could be assured of this, but since I rent there's no guarantee that the previous 'renter' followed the checklist. Still, the basic point is 'the next time you start' that nothing electronic should be 'on'.
#3
In every car I drive I turn absolutely everything off also before I exit the car... mostly out of habit from my youth when I drove a series of crappy $500 cars that had such bad battery/alternator issues that you couldn't start the car if anything else was on.
#5
Registered User
I have heard that the a/c system will get a surge when you crank the car if you dont turn it off, i dont know if this is true or not but on a couple of my hondas that have over 200k miles we have always turned the a/c off and the systems are still working well. Usually thats the first thing to go on a japanese car. So there may be some truth to it.
#6
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There is another reason why I trun off the AC at least a few minutes before shutting down the engine... For the purpose of drying out the moisture on the evaporator, to minimize the chance of mold growth.
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#8
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I turn everything off except the radio, which I leave on but turn down the volume.
#10
Three Wheelin'
Someone here probably knows for sure but I think the 993 CCU automatically shuts the compressor down at start-up. Most modern cars do this for the obvious benefit of faster cranking when you're not turning the compressor and pulling an electrical drain on the A/C clutch. Even on earlier cars most starting systems were designed to isolate the Acc functions when you turned the key to energize the starter so as to give full electical boost. While the small, marginal load on a just started cold engine may not be a big help, I would think the benefit of no electrical load after it fires is negligable as long as your battery and charging system are up to snuff.
#12
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Someone here probably knows for sure but I think the 993 CCU automatically shuts the compressor down at start-up. Most modern cars do this for the obvious benefit of faster cranking when you're not turning the compressor and pulling an electrical drain on the A/C clutch. Even on earlier cars most starting systems were designed to isolate the Acc functions when you turned the key to energize the starter so as to give full electical boost. While the small, marginal load on a just started cold engine may not be a big help, I would think the benefit of no electrical load after it fires is negligable as long as your battery and charging system are up to snuff.
#14
Been doing this for years, and haven't had an A/C on my cars fail yet. My Tundra has 140K and is a 2000 model and the A/C is super cold. Plus mold stinks and makes me sneeze.
#15
Drifting
...I think the 993 CCU automatically shuts the compressor down at start-up...2Many Cars
Last edited by Rinty; 10-21-2008 at 09:09 PM.