[paulca]

It's best to just hit AUTO and let it do it's thing. It's quite smart at knowing how to achieve what you probably need done, if that makes sense. Here's a few things it does in AUTO.

Get into the car when it's cold and set a temp higher than ambient, it will stop the fan and wait until there is hot air to give you. It will select "Feet" or "Feet and Window" depending on humidity and temperature. When the coolant is warm enough to provide hot air the fan will rise. The bigger the temperature difference between selected and actually the faster it will run the fan, blowing more hot air. When the temperature in the car rises it will lower the fan speed until it's just enough for airflow and maintaining temp. When the temp matches it will switch to feet and dash vents. If the temp rises above the selected temp it will switch to the dash vents only and introduce the AC for cold air.

Similarly if you get into the car on a hot day and select a cool temp it will stop the fan and wait until the AC can actually deliver cold air. It will switch to dash vents. Then the fan will rise to a setting reflecting the difference in selected temp and actual temp.

The AC will show a green light when it is "made available" to the climate control system. If you press it, it will go off and (mostly) stay off, unless you select the defog mode which forces it on again.

The AC is used for two things. Cooling and drying. So even on a cold day when the car is producing hot air for you the AC will cycle in for 5 seconds once or twice a minute to dry the air. I hear a lot of people complaining about the car steaming up, these people are usually the ones who turn the AC off. Leave it on and the car never steams up.

The other thing under AUTO control is the recirculation valve. If there is a large difference between the selected temp and the actual temp it will sometimes close the recirc until things improve, then it turns it off again. I haven't quite figured out the exact conditions that triggers this but it does it.

My advice is to select AUTO, set a temp you want and leave it alone, let it do it's thing.

If you DO want to override it, it allows you to override any setting, as soon as you change the fan speed or air vents in use, the AUTO mode disengages and only maintains the air temperature. Just hit AUTO to get back to full auto.

AC and Recirc do not disengage AUTO, but will hamper it's operation if changed from what AUTO choose.

Tips: If you suddenly want full hot and full fan, just spin the temp dial to "HI" and it will go flat out heat. If you suddenly want full cold, spin the dial to "LO" and it's flat out cold air.