I noticed the other morning when it was in the 40's, I set my climate control for auto at 72 degrees and it still had the a/c lit on the display. I shut it off manually then it was fine. If I hit auto again, it kicked the a/c on. Does it measure the amount of moisture in the air or just temp? Is it normal to operate like that?

 

My 05 F250 does the same thing. Manually can adjust to anything but if you hit auto the AC comes on.

 

It is normal operation of the system. Even the manual climate control operates the A/C in all but one or two positions. A/C is used to control the amount of humidity in the air to prevent windows from fogging up and will normally cycle on if the outside temp is above 32 or so.

 

My 06 does the same thing. In Auto mode the A/C is always on. I suspect it's "controlling the climate" including humidity and therefore window fog. Blowing dryer air into the cabin.

 

Good to know. Thanks!