e240 w210 reading light frequency sound

[sherco450]

the high frequency sound coming from the centre ceiling reading light unit is becoming unbearable that the radio wont even mask the sound . before l get stuck into pulling the unit apart .. any help will be great thanks

 

[Dieselman]

It's the ambient temperature sensor fan.

 

[sherco450]

were is the little puppy hiding, behind the light globes or does the whole unit need to be removed. sunroof switch ect. thanks