Well, winter is coming and it's starting to get cold. Yet I'm driving with the climate control in auto and the A/C is always on. Unless there's a reason for it (high humidity in the cabin) this seems to be wasteful and would cause unnecessary wear on the A/C unit. Do most people operate in manual in the winter? Or is there a reason for leaving the A/C on all year round?

 

I believe that when you have the system set to auto the compressor should switch off and on as and when it is required. The red lights on the climate panel will stay on all the time though.

 

I owned my car about seven years and I probably had the air conditioner on about 99% of the time. I never had any trouble with the A/C unit and it always worked great. I think that might have been the first car I ever owned that didn't at least require a refrigerant charge. Not sure if having it on all the time had anything to do with it, but I my guess is that maybe having it on and having all the parts moving helped keep everything lubed up. I couldn't tell you if that had anything to do with it as I am not that technically savvy, but I look at it like a car that is not used for a long period of time. It sits around and things start to deteriorate from lack of use.

Having the A/C on even in winter takes the humidity out of the air. You have the windows closed and especially if you have the recirculate button on, moisture gets in the air just from you breathing. After a while you can see the windows start to fog up. That won't happen with the A/C on.

 

Rapala and Alfadude are right.

The A/C light will always be on in Auto, but the compressor clutch will only engage when necessary- more on a cold damp day than on on a cold dry day. I've had our X type from new 11 years ago and it's always run in Auto. It's never been recharged and still churns out really cold air if required on a hot (UK!) day.

Jaguar recommend keeping the system in Auto in the handbook. The fact is that in Auto, the system is cleverer than the driver in getting the car interior to and maintaining, the selected temperature. Occasional use of the Defrost button may be necessary first thing on a bad day to clear the screen, but not for long, then back to Auto.

 

And it will cycle the AC once in a while regardless of the temperature. If you move the gas through the lines, the oil in the gas keeps the hoses pliable and sealed up.

If you have a regular car without the auto, cycle it for a minute or two once a week in the winter and you'll stop losing refrigerant in those systems, too!

 

I live in Florida and believed that running the system with the A/C off in the winter would be much more efficient and effective. I was wrong.

I tried using the defrost in manual, purposefully turning the A/C off. The windows fogged worse than when the A/C was on (since the moisture in the air was no longer condensed before it passed through the vents).

The humidity here, even in the winter, was sufficient to fog my windows when I ran the system with heat on and the A/C off. I now simply set the desired temp using the climate control in auto or defrost allowing the A/C to cycle as necessary to reduce humidity, and enjoy fog free window driving during the colder months.

Needless to say, the summer months are always Climate Control in Auto....

 

Depend on what temp. do you set on the auto. it run by the interior temp., even you feel little cool out side, but if auto. sensor feel inside warmer (the sun ray) the temp. you set it will runs to cool the air down, if the inside air is cooler the temp you set it will run to keep it warmer, when you set the temp. on auto it's not just run the A/C but a climate control, it will run all the time to keep interior at the temp you set.