Auto always turn AC on when heating? How to disable it

Yes, just quit using auto if you do not want the car to make the best decisions it can. Auto just means the car makes the choices, I override auto a lot. Mostly about which vents to use.

 

Press the AC button to turn it off. AUTO will stay lit and still work. This will not work if you're on the foot and windscreen setting because of what you already explained is stupid. In winter, I set AUTO to go to foot only and no AC.

 

You're basing your thinking on the mistaken assumption that the compressor is running at all if its not needed. The light only indicates that its ready to run if needed. Some later models changed that behavior and turn the light off too, but the performance is the same. Use auto or don't, but don't make that choice based on the thinking that the compressor runs at all.
And as stated, you can still turn the A/C off and remain in auto mode. It will stay that way till you press auto again.

 

You do need it for defrost operations especially down south where the cold air often is humid initially and you need to see now, not later.

 

I do what @mmmodem does, mostly. You do want to run AC occasionally tho, to keep it's oil circulating, lubing seals. Using heat/defog mode will likely use some AC on the sly, as he mentions.

 

hj630, The compressor is enabled when using heat to dry the air in the cabin, preventing frosting... especially when there'e more than 1 person in the car. When mine comes on, I make note of the outside air temp and if its above 50F, I manually turn the compressor off. The AUTO function still regulates the cabin air temp quite fine.

 

I have never seen the usefulness of the Auto setting. You can set the temperature manually along with the fan speed and leave it there all winter. If you need defrost, push the button, knowing that the a/c compressor might run. It is variable speed, and not a huge energy user in defrost. Auto lets the car decide, which I do not care to do. In the Gen3's, you cannot disable the a/c when in defrost, and the a/c light does not come on. It may be different in Gen4.

 

My ford f150 pickup runs the compressor when defrost is turned on. Don't most ?

 

Chill.

Just because the light is ON doesn't necessarily mean that the compressor is running.
Seems to me like a real Engineer would know that.

If it makes you feel better, take your finger and push the button to turn it OFF when you think it is not needed.
But the car actually knows when it's not needed........and in general it doesn't run when it shouldn't.

 

On our third gen, monitoring with scangauge, if the AC light is on, the compressor IS running, off-and-on. I guess barring below zero temps where the computer will shut it down.

I was a draftsman, then a checker, lol.

 

Yup, it IS running but the duty cyle\cle is low, meaning it is off much more than it is on. Still not a significant draw on the traction battery.

 

Did anyone answer the question "how to disable the a/c compressor"?
I need to "disable" compressor running in the winter.
I get it... But my wife doesn't and I can't get her to turn off the A/C button in cold weather.
Yes, the challenges are great here.
The fuse under the hood is blocked with the engine cooling fans. Can't remove that.
Inside A/C fuse controls other stuff so I can't pull that one.
May have to unplug at the compressor...
Any other ideas? Is there a relay that I haven't located that would do the trick?
Thanks!

 

Yea the air in winter up north is dry but when people get in with snow you bring the humidity into the car with you.

The more people the more humidity, that's why your floor mats are wet.

 

@RXZOOMM Disabling the AC compressor might put her in danger: there are some weather conditions where AC is pretty much the only thing that'll clear the windshield fog. I would just persevere about when to use it.

 

You are making something out of nothing. The system is operating exactly as it is designed, leave it alone. The compressor itself is only running for a very small fraction of the time the light is on.

 

Monitoring AC Watts with scan gauge I found that fraction was around 1/2, at various levels. But it's a moot point, I would never disable it, just a bit more education about when and how to use.

 

Can turn that off in settings on the Prius C. Check your settings and see if the same option is available to you. Worth at try at least.

 

You "need" to do no such thing.
Even though it's "ON" it shouldn't actually do much most of the time.
But it NEEDS to be available for defrosting and dehumidification..........and even battery cooling in some conditions.

REALLY BAD IDEA.

(And it might be an even WORSE idea to keep pestering your wife about it.)