the button is on when auto is pressed because that was how auto was set up. you can have the a/c button on and still have hot air blowing out (the stratification wheel at the upper center of your dash b/w the vents) can be set at hot. ive also heard of people saying their heat doesnt work, full blast at 90 deg. and the wheel is set to cold. i dont remember if the compressor runs or not, but im thinking that it means it is. just do a test. idle and press the autop button. if the idle increases when auto is pressed (and AC on) then the compressor is running. if the idle stays the same, then its not on. (hope this helps!)
