The car decides whether you need A/C or heat depending on the termperature you've selected vs. the temperature it senses in the cabin (and probably also the outside temperature that it detects via a sensor under the nose).

There's no actual "A/C" button per se; the closest thing to that is the "AUTO" button, which allows the A/C compressor to run if the car decides that it needs to. Pressing the "Manual" button keeps the compressor off (i.e. no A/C), although heater operation is not affected.

I have '92 SSE. That is about the ONLY thing I do not like about my elec climate control. You really can't control where the hot air comes out. Man, I wish I could get warm air from the upper vents too. As far as I know it is either warm front widow or warm feet....no inbetween.

I sure hope the 2000+ models allow that. I'm getting ready to trade up........finally.

*ack* Brain fart... There's no Manual button, right? I must have been thinking of the ECONomy button, or whatever the heck sits in between the AUTO button and the windshield defrost button in the little row below the display...

climate controll
 

i have the same problem, and you just have to play with it for a while, i still havetn mastered it, and ive had mine for 2 years. sometimes it does what i want and sometimes it dont. then i get mad and stop playing with it

Re: climate controll
 

Right, you don't get to pick which duct(s) the air blows through, except for the Defrost setting which overrides and sends all air to the windshield ducts.