acastell

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...

g_murray

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'.

Denise993

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.

Texas993

I don't turn anything off. I did in my Ferrari, but they have crappy electrical systems.

Boeing 717

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.

Novice

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.

Mike in Chi

Ditto.

CADguy

Yes, I have just heard about doing this. It is also supposed to reduce that "air conditioning smell" the next time you fire it up.

I turn everything off except the radio, which I leave on but turn down the volume.

993Maineiac

+1 to the turn it all off crew. It reduces drain both at shutdown and startup.

2Many Cars

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.

acastell

May thanks all...off it is!

Bull

You are correct, just as the radio is interrupted when you start the motor.

Phil

ditto?

when was the last time you used your a/c?

BufordTJ

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.

Rinty

The compressor engagement is delayed 30 seconds or 10 seconds after engine startup, depending on outside air temperature.