Mystery tube

[LamboV8S]

Hi,

What is the tube that connects up to the light/sunroof switch unit? runs down the n/s a pillar?
Lambo

 

[BillyW124]

Its a cabin air temp sensor

i havnt the foggyest how it works though, it draws cabin air through there but im not sure what it does after that!

ive got it too on my 124 and i havnt got a/c nor climate.

 

[coalville126]

Regardless whether it has aircon / climate or not, the tube connects to a small fan which draws airs onto a temperature sensor. Depending on the cabin tempeature, it regulates the mono/duo valve to let more or less hot water through to the heater matrix to maintain the temperature as set on the thumb wheel.

I'm sure someone more knowledgeable than me will come along and correct me if I'm wrong.

 

[LamboV8S]

Thanks for the info chaps!

Lambo