E220 C207 Coupe. Fan/compressr runing on when parked.

[Scooby_Doo]

I've had the car for nearly 18 months and have had no problems with it. The only niggle is that when it's parked ( always in the garage) and the car's unlocked there seems to be a fan or compressor running,sometimes for up to an hour after it's parked. Locking the car will normally stop it after a few minutes whether the engine is hot or cold.
If I open the car the next day then the fan/compressor comes on again and , whilst I haven't actually timed it , will stay on until I lock it again,even if I don't actually start the car.
I have pointed this out to my local Dealer on two occasions and been told that, after they checked with MB GB, that the fan is meant to cool the headlamp units as they have LED DRLs. Plausible because you can feel the vibration in the headlamps .
Any other member noticed this issue on their car ??

 

[Scooby_Doo]

Thought I'd try this again.

Also noticed yesterday that whatever is running it also happens if I only open the boot when the car is parked in the garage. Keeps going even after it's shut again. I'm a bit dubious now about what the Main Dealer told me about the lights.