Air Conditioning Confusion

I have just switched from a '03 CLK to a '60 S350. I've been puzzling over the air con as it wouldn't work in the hot day we had on Thursday. The manual has a slightly different layout to my car and is not easy to work out (for me anyway!)

There is an on/off switch, an auto on/off switch and an on/off as part of the COMAND AIRCON function. Can someone please explain how they should be set up for it to work?

I also can't work out how to have the air con off but "plain" heating/ventilation fans running.

I read elsewhere in this forum that MB have changed the air con light so that illuminated is now on. Not on mine.

Any help much appreciated.

Martin