[Ranger 6]

Huh?
A/C should only come on when there is a need to cool/chill the air. If you press the A/C button when there is a need to warm/heat the air then of course it won't come on.

Climate control is simply a complex series of sensors which controls the A/C automatically and switch between heating and cooling to manage a fixed temperature setting.

Just switch on the A/C in Auto mode, set the recirculation to Auto as well and leave it alone. Messing with it and switching it on and off is what will knacker the compressor and seals not the temperature.