Not all used cars have the owner's manual.

Actually, this is very easy. Set the temp you want on the dial (noting that some run hot and some run cold -- I have to set the 300D to about 80 to keep from freezing in the winter).

The ACC will maintain that temp automatically, running the heat, the AC, and the vents as appropriate. Only cold air will come out of the center vents, they close when AC isn't called for.

The horizontal row of buttons are, from left to right, Defrost (all air out the windshield vents, full heat, full fan when engine temp is above 50C); "bilevel"
where some air comes out all the vents (good for winter, more dash air so you don't have a cold breeze off the windshield, and more cool air on the floor in the summer); "normal"; and Economy -- full climate control but no AC compressor.

The three vertical buttons are fan control. Bottom is low speed -- don't use in the winter, you will freeze! Middle is auto, top is high.

You will notice the following: in automatic mode, you won't get a fan or much heat until the engine gets to 50C. Use defrost or bilevel if you want cold air blowing on you on a cold day. There is a delay on startup when hot, it takes a minute or so for the AC to start.

After shutting off in the summer, you will get a blast of heat when starting the car, the heater valve is held colsed by voltage, so the heater core gets warm when you shut the engine off.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!