In the spirit of "There's no such thing as a dumb question", is there a place to lookup the operating instructions for the climate control system in my car (red/blue wheel, row of horizontal arrow buttons, fan settings, white button that says automatic)?

It's not a dumb question.

The blue/red wheel is the temperature wheel. Depending on which CCU you have installed, it'll be marked in Centigrade or Fahrenheit. Blue is A/C, white is mixed, red is heat.

Fan switch is Max or Min fan speed. Pressing "Automatic" will allow the CCU to vary the fan speed automatically depending on setpoint and current cabin temp.

Mode buttons left to right: Defrost, Defrost/Floor, Automatic, Economy, Off.

Defrost defaults to max fan/heat at the defrost nozzle at the windshield. Defrost/Floor will run in automatic mode to maintain temperature using defrost and floor vents. Automatic will vary the vents in use depending on temperature in the cabin, temperature outside, and the desired setpoint. Economy is the same as Automatic, but disables the A/C compressor. Off is just that - Off.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Thank you.

I'm having a problem getting heat. I had the heater valve replaced last week, but it is still doing the same thing. When I call for heat, hot air comes out for about 20 seconds, then cold air. Have any thoughts?

Did you use a genuine MB monovalve cartridge? The aftermarket ones are known to have lots of issues.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Not sure...had it done at local shop...will ask...thanks again.