climate control knob

[sohile]

Hi guys,
i am new here, i need your help, the climate control knob is on the max cold and the air coming out is ok (cold) , then by just rotating the knob clockwise by one step to get less cold air the air becomes so hot as if i am putting the climate to max heat. I also noticed that at night this knob doesnt light like before, but the small horizontal led in the knob is ok its lit when the ac is on.

Plz advise.
Thanks