This is for a 1980 300SD, 116 Body. The A/C controls in the passenger compartment are the buttons in a column, it also has the A/C servo in the engine compartment.

The A/C is cooling very well, but it is either on or off. I have no control over the temperature. And my daughters tell me there is no heat. It is in the 90's here in FL, so I have not verified that.

I am looking for guidance on where to look first.