UNKNOWN part on 91 500sl
 

can anybody help me out with identifying what this part is? What does it do? What are the implications if it is missing from your car. All help appreciated.

part # 129 830 04 08

more info
 

oh by the way, his part is located in the area where the interior lights can be found, near the rear view mirror

That device is the in-car temperature sensor for the automatic climate control.

questions
 

ok thanks, but what does it do? What are the implications if it is missing?

In-car temperature sensor
 

It measures the temperature inside the car for the ACC. When the convertible top is not open, the controller compares this value to the temperature selected by the passenger to regulate the temperature of the air passing through the air vents. When the top is open, the controller disregards the sensor and assumes a constant temperature of about 72 degrees.

If the sensor is disconnected, the controller will recognize this. I don't know, but I will guess that it would operate as if the the top were open.