I have a 2011 4.0L Ranger. The vent control has (in addition to normal AC, defrost settings) a setting for upper vent, lower (floor) vent, and one for upper/lower. My question is if my AC compressor should be engaged in the upper/lower setting. It's off on the lower and upper settings but comes on when its set to upper/lower position. Local mechanic says it shouldn't come on - probably a bad switch. Any thoughts?

 

My A/C always came on in the upper/lower position too. Not too sure why but I was never too concerned about it. Just remembered to turn it to defrost/low when A/C wasn't needed.

 

vehicle operating as designed, my 03 and my current 98 are the same way