OK, your ACC buttons;

Left to right, Defrosing windscreen, Air up and down, Normal (most air down) Economy, Off.

Fan buttons top to bottom, Max fan, auto mode, minimum fan.

As you have ACC - NO heated air will come out of the rear center vents, it will come out of the vents under the front seats. I add this 'cause many complain about the rear seat being cold and have blocked the rear under seat vents with mats.

86, that 'wheel' in the console is for the speaker fader (if still connected).

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1988 W126 420 SE

beware of fundamentalists!