help required - instrument cluster w220

[Chas]

Many thanks.

My car is under extended warranty, and they (warranty direct) say they will replace the cluster through MB dealership. Looks like a win win situation if the cluster is knackered.

cheers

Chas

ps

I still wonder how that little bulb in the top left position can illuminate the whole cluster?

 

[Howard]

I was wondering that too ....

Unless there is a fibre optic thing going on , one light source and it illuminates lots of stuff that way ?

 

[MBManInKen]

It's not just a single bulb, the segments of the speedometer light up individually and when using speedtronic or the cruise control, corresponding segments will light up.

 

[Chas]

Its not just the speedo, its the whole cluster white lighting! Beginning to think the cluster is knackered

 

[MBManInKen]

Its not just the speedo, its the whole cluster white lighting! Beginning to think the cluster is knackered

Sorry, yes, I understand and that bulb might very well play an important role in that, but I wanted to point out that if the whole cluster is dead, there is more going on than just a blown bulb. Unless the rest of the circuit was in series with that bulb, but that would be rather bizarre design...

 

[Chas]

The cluster should look like this on top

but looks like this one on bottom (air brushed examples, not actually mine)

The white on mine looks almost grey and barely lit

I do have indicator and warning lights since I replaced the blown 5 amp fuse

 

[MBManInKen]

**edit**

 

[MBManInKen]

By the way, this is my cluster:

(Daytime obviously). From your pic, I'm missing the external temperature gauge and the gear setting indicator next to the clock.

Obviously, there are also the warning lights left and right, of which in the above you can only see the brake one as the parking brake was on when the picture was taken.

 

[Chas]

The bottom pic is all I can see (except for warnings and red brake indicator)

 

[MBManInKen]

OK, so the segment lights and the warning lamps still function. I guess it is possible that a single bulb supplies all the rest of the backlighting through fiber optics.

It's easy enough to take the cluster out if you have the removal keys and that should give access to the bulb in question?

 

[Chas]

Just the segment lights in the bottom photo can be seen, the rest are dead

 

[Dieselman]

I still wonder how that little bulb in the top left position can illuminate the whole cluster?

It doesn't. The Diagram key says there are 5 used.

They look like the warning lamp bulbs to me, I think the main backlight is lit by an electroluminescent plate, or similar fluorescent type lamp.

 

[MBManInKen]

It doesn't. The Diagram key says there are 5 used.

Is there any publicly available detailed diagram of the cluster? I've always been interested by it since Mercedes claimed it was an innovative design - and it does look quite different from older designs. But I can't find any detail on the web.

 

[Chas]

Looks like the cluster then! MB never got back to me, I will see them tomorrow.

thanks for help everyone.

 

[Diesel Benz]

It doesn't. The Diagram key says there are 5 used.

They look like the warning lamp bulbs to me, I think the main backlight is lit by an electroluminescent plate, or similar fluorescent type lamp.

The back lights should be from cold cathode fluorescent tube lights. The high voltage switchers tend to fail, the transformers specifically. Some parts sources have spare parts but there are several different options and quite a difficult soldering task to replace those parts. I did not find any good reference but some idea here:
http://en.wikipedia.org/wiki/Cold_cathode

Edited, one spare part with some info here:
http://www.ecplaza.net/tradeleads/seller/5413817/trans_8948411098.html

 

[Dieselman]

Is there any publicly available detailed diagram of the cluster? I've always been interested by it since Mercedes claimed it was an innovative design - and it does look quite different from older designs. But I can't find any detail on the web.

I meant the EPC diagram. The key denotes 5 lamps are used.

Anyway..this is all I find with a quick search using the P/n Diesel Benz has highlighted.

http://www.codecard.lt/dash/transfo...ment-cluster-illumination-repair/prod_40.html

Fit two BUZ102S and a transformer and you should have a fix.

 

[Chas]

I took the car in today to MB. My car is not on "problem list".

Hopefully they will take a sympathetic view as I am a valued customer

 

[Howard]

If MB won't wear it and you have to splash for one yourself , try speaking to Nick at Euromerc .... they've got at least one for a 220 , may have others , you would need to match the part number though.

http://cart.euromercmercedesparts.co.uk/index.php?p=product&id=691&parent=14

 

[Dieselman]

If MB won't assist buy the transformer and a set of transistors. Get 4 transisitors as I'm not sure how many it uses, but the total cost should be about £60.

 

[Chas]

If MB won't assist buy the transformer and a set of transistors. Get 4 transisitors as I'm not sure how many it uses, but the total cost should be about £60.

Does it require any soldering, or can they just plug in? Do you know where I can get them in the UK?