Leaving AC turned on when turning the engine off

[SFM]

I've been wondering if it hurts to leave the AC on and just turn off the engine so the next time you remotely start the car the AC turns on by itself?

If it won't hurt the car then that's going to help a lot since I need the car to cool down a bit before getting in it.

 

[Stinger GT SS]

Double check the owners manual, but I believe it should not be a problem leaving the AC on when you switch off & restart the car.

 

[Bigbikes]

I've been wondering if it hurts to leave the AC on and just turn off the engine so the next time you remotely start the car the AC turns on by itself?

If it won't hurt the car then that's going to help a lot since I need the car to cool down a bit before getting in it.

How do you think it would harm the car in anyway...aircon only runs when engine is running as motor turns compressor motor over...So no is the answer your seeking..

 

[ShannonC]

In my experience it makes no difference.

 

[SFM]

How do you think it would harm the car in anyway...aircon only runs when engine is running as motor turns compressor motor over...So no is the answer your seeking..

I was just worried about it making the startup harder on the engine.

 

[eflyguy]

The AC compressor is not going to engage until the vehicle is running.

 

[oddball]

This ain't your father's Oldsmobile.
The A/C compressor on all modern cards is controlled exclusively by the ECU. The panel in the dash simply "requests" that the A/C be engaged. The ECU determines when it's appropriate.
So the A/C clutch is *always* disengaged when the engine starts, and the ECU will engage it after it's happy - usually about 5 seconds.
I just have the climate control set on auto and never touch anything, except for the few days where the windshield fogs up.

 

[Metalmania82]

I have a slight OCD issue. I like to turn everything off before shutting the car down, usually while sitting a minute or two to let the turbos cool down a bit instead of just shutting down after a hard run or long drive.

 

[Rynil2000]

This ain't your father's Oldsmobile.

OMG - THIS. My FIL, and wife by proxy, have always been adamant about "turning off everything before turning off the car." There is simply no reason now to turn off the radio and climate control prior to shutting off or turning on modern cars. Plus it's super annoying to get in a car that is stagnant and silent. /rant

 

[Capital AL]

Modern cars have relays to prevent anything bad happening. It is perfectly fine to leave the A/C running when you turn off the engine.

 

[Fatalifeaten]

Think about it this way. When you get in and manually start the car up, the cabin fans don't even kick on until the systems check completes. That's a minimum 5 seconds after engine start. I can tell you from experience that's a very long 5 seconds in the summer in AZ. Same with the remote start. It's all good under the hood. leave it on if you want.

 

[SFM]

I've been wondering if it hurts to leave the AC on and just turn off the engine so the next time you remotely start the car the AC turns on by itself?

If it won't hurt the car then that's going to help a lot since I need the car to cool down a bit before getting in it.

Think about it this way. When you get in and manually start the car up, the cabin fans don't even kick on until the systems check completes. That's a minimum 5 seconds after engine start. I can tell you from experience that's a very long 5 seconds in the summer in AZ. Same with the remote start. It's all good under the hood. leave it on if you want.

Thanks for the help!

 

[Capecod]

This ain't your father's Oldsmobile.
The A/C compressor on all modern cards is controlled exclusively by the ECU. The panel in the dash simply "requests" that the A/C be engaged. The ECU determines when it's appropriate.
So the A/C clutch is *always* disengaged when the engine starts, and the ECU will engage it after it's happy - usually about 5 seconds.
I just have the climate control set on auto and never touch anything, except for the few days where the windshield fogs up.

Not sure but does the ECU also adjust fan speed on incoming calls over BT, I thought I noticed that happens?

 

[robz32]

It used to be an issue on older cars. Pre-1990 old.
No issue on newer cars.

Not sure but does the ECU also adjust fan speed on incoming calls over BT, I thought I noticed that happens?

Not the ECU but the infotainment computer, but yes the fan speed is lowered when you are on a BT call.

 

[Mike_TX]

People still worry about this? My AC is never turned off, all year round. I start and stop my car multiple times a a day and have for decades. It has never hurt anything in any of my cars. Don't worry about it.

 

[Gtecko]

I always thought the car would explode if I remote started it and forgot to turn off the A/C beforehand ......... wow , I feel better now.

 

[oddball]

It used to be an issue on older cars. Pre-1990 old.
No issue on newer cars.



Not the ECU but the infotainment computer, but yes the fan speed is lowered when you are on a BT call.

Yeah, my first love, the '72 Cutlass, I do have to turn off the A/C when I shut it down. Actually about a half mile before I stop to get the heat out of the condensor. At some point it'll get a fancy fuel injection setup where the ECU will actually control the compressor so I can forget about it.

It also lowers the fan speed when the sunroof is open, and lowers the fan even further while the sunroof is opening or closing to protect our sensitive ears.

 

[Capecod]

I recall having to turn the AC off to pass another car on the HW

 

[Dennis]

Stinger runs on newer generation of Swash plate or axial type compressor which means there is no clutch it is actually always engage only difference is when ecu sends signal when condition are right to allow the Swash plate to interact with the pistons to create a suction effect. This can only happen when the ecu senses temperature, operating condition are met before operation. The older clutch engage compressor will require turning off to prevent load when starting the car. The new generation compressor has already been use in Kia cars since 2013 for efficiency and accuracy to regulate temperature. Hope it helps.