CL500 C215 2004 Interior Dome Light

[Meatfeast]

Hi all.

I was having an issue with a battery drain in my car.

My local Mercedes specialist traced the fault to my Dome Light, so I purchased a used one from eBay rather than pay £700+ for the privilige of owning a new one!

I had the replacement Dome Light fitted but now I seem to be having a problem with the Climate Control. When the Air Con is on low, its all good, icy cold and excellent. The issue is as soon as I take the stting from low even up just one setting, the blower instantly starts blowing warm/hot air! As I understand ithe the Climate Control is regulated by a fan in the dome light, so my question is are there any fixes for this?

Any suggestions would be much appreciated.

Cheers All.

 

[alexanderfoti]

Needs to go on star to check the actual values.

There are two interior temp sensors, one in the fan and one in the climate unit itself (small vent in the corner). You need to read what these sensors are seeing.

If not, then the duo valve is sticking.

 

[Meatfeast]

Needs to go on star to check the actual values.

There are two interior temp sensors, one in the fan and one in the climate unit itself (small vent in the corner). You need to read what these sensors are seeing.

If not, then the duo valve is sticking.

Thanks for the information.

Do you know if the Dome Light is servicable, i.e. it can be opened up and cleaned out etc?

 

[Craiglxviii]

Thanks for the information.

Do you know if the Dome Light is servicable, i.e. it can be opened up and cleaned out etc?

I had to replace my whole UCM (upper control module). Iirc it can be entered but many components are heat staked in place.

 

[Borys]

Thanks for the information.

Do you know if the Dome Light is servicable, i.e. it can be opened up and cleaned out etc?

When you open it up only thing you can check visually and fix is the two tiny wires inside the fan….they tend to brake or can be totally clogged up with dust. Otherwise Star and replace. Unfortunately I went through 3 on mine, all good now

 

[Meatfeast]

I had to replace my whole UCM (upper control module). Iirc it can be entered but many components are heat staked in place.

Which is the UCM bud?

 

[Craiglxviii]

Which is the UCM bud?

The unit with the dome light and sunroof switch in it.

 

[Meatfeast]

The unit with the dome light and sunroof switch in it.

Thats what I replaced bud, there was a power drain detected on the original unit so I bought a s/h replacement, now I have no power drain but the climate control doesn't work properly, its either freezing cold when set to ‘Lo’ but as soon as I raise the temp by even one degree it only blows hot air.

I think maybe the UCM I bought is faulty.

 

[Craiglxviii]

Thats what I replaced bud, there was a power drain detected on the original unit so I bought a s/h replacement, now I have no power drain but the climate control doesn't work properly, its either freezing cold when set to ‘Lo’ but as soon as I raise the temp by even one degree it only blows hot air.

I think maybe the UCM I bought is faulty.

Quite likely!