CL500 C215 Dome Light Issues

[Meatfeast]

Hi all

I have a 2004 CL500.

I keep my car on a C-tech charger when it’s on the drive and not being used, I was told to do that when I bought the car last December by the seller.

Recently I had an issue where one night I forgot to plug the car in and when I came to start it the following morning the battery was completely flat.

I managed to plug the trickle charger back in and eventually I managed to get enough charge into the battery to fire the car up. I then took the car to my local specialist in Stockport who diagnosed a battery drain that was traced back to the Dome Light fitting at the front of the car.

I‘ve noticed a buzzing sound coming from the light fitting whenever the ignition is switched on, but when I turn off the ignition and open the door the buzzing stops. I was advised to purchase a new Dome Light fitting at nearly £800! - however I’ve purchased a really decent second hand unit and I’d like to know how easy is it to swap over the units and also if anybody knows what the buzzing sound could be?

Any help would be greatly appreciate.

Many thanks.

Kindest regards.

 

[alexanderfoti]

There is a small fan in the dome light fitting to sample internal air for the climate control. The fans do get noisy.

I have not had a light fitting cause battery drains on these. It is a straight swap.

I'd also would have thought that the small internal fan would not be able to drain the battery overnight either.

 

[grahamcol]

The fan referred to in the post above should switch itself off once the car has stood locked for two or three minutes. At least that's how it behaves on my CLK

 

[Blobcat]

Aspheric motor is the fan, as per Alex above its for sampling the air for climate control