How to for climate control 1985 300D
 

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.

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.

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