Can anyone tell me if it is difficult to replace the interior temperature sensor (near the interior light) on a 1986 190E 2.3.
Is there a written procedure some where or is it easy enough for a online description. Is there an easy way to test the sensor before replacing it. My heater will heat very well and cool very well but there is no control. To get the air conditioner to work I push the button above the * button on the control panel and it turns the air conditioner on full cold out of the center console.
The rotary temp setting switch has no effect on any operation of the heater. I have no control except fan speed and outlet settings.

Thank You for a response.
Don Umble