Delighted!

[Razoo]

2004 E320 CDi Avantgarde

I decided to spend some time putting right some of the annoying things that go wrong, even when you don't use them.

The driver's vanity light (above the sun visor) didn't work, so I bought a new bulb, figuring a blown bulb would be the most likely cause. Of course, it wasn't.

I took the bulb out and checked the voltage across the bulb holder. It was a little over 12V. Put the bulb back in and noticed it was just glowing very faintly.

I guess there must be a poor/high resistance joint somewhere that is preventing the bulb from taking its normal current. Either that, or I've lost the earth connection and the bulb is finding a return path via some other component.

I hope MB have kept the circuit simple: 12V supply, series switch in the mirror flap and a bulb.

Does anyone know the circuit, or where I might look for the fault?

Thanks,

Razoo

 

[ernieh]

Vanity Light

I suggest that you check the contacts on the outer clip of the sun visor as a high resistance there will give the sympton you are experiencing. Just to try and explain further....where you unclip the visor to swing it to the side, there are a pair of contacts at the pivot which prevent the lamp coming on when the visor is unclipped. I would try some switch cleaner as a first try.

Hope this is clear and that you find the fault.


Ernie

 

[Razoo]

I suggest that you check the contacts on the outer clip of the sun visor as a high resistance there will give the sympton you are experiencing. Ernie

Hi Ernie,

Thanks for your suggestion. I did spot the two contacts on the sun visor clip that (presumably) provide the +12V supply and return for the microswitch actuated by the mirror flap. The contacts checked out OK, as did continuity through the microswitch.

I was hoping to obtain the circuit schematic before I probe too deeply (MB have a tendancy to over-complicate designs unnecessarily, and I don't want to make any assumptions about how the lamp is wired).

Mike (Razoo)

 

[Blobcat]

I would try cleaning the microswitch as I had the same issue in my W210

 

[Razoo]

I would try cleaning the microswitch as I had the same issue in my W210

Thanks Blobcat - an excellent, informative link.

Good photos too. I hate plastic 'unclippy' things that usually break their little tabs during removal, so that you can't refit them. It's good to know where the tabs are hidden.

Razoo

 

[Hertfordshire Merx]

Maybe a good idea to replace the contacts which come with the mounting mentioned above. I have replaced a few of them in the past as they grow extremely weak when the visor is being used during the summer months..

 

[Razoo]

Maybe a good idea to replace the contacts which come with the mounting mentioned above.

Can you actually buy just the contacts from MB? I'm amazed (and impressed). Usually car manufacturers would insist on selling at least a complete sun visor assembly.

I remember with fondness that policy being applied by Vauxhall for Senator spares.

Vauxhall would only sell me a complete light switch assembly at £36 + VAT, when the internal wire ended bulb blew, because the bulb was a non-serviceable item (because it was soldered in!)

Then, when the fan speed slider switch contact block fell apart (mainly because it was an inadequate printed circuit board design that couldn't handle the current), Vauxhall would only sell me a complete air-conditioning fascia at £104 + VAT. Yet the contact block I needed was a separate item held on by two self-tapping screws!

RS Components solved the first problem with a 30p wire-ended bulb, and Araldite and a second-hand fan control relay from a Jaguar XJ6 solved the second.

Razoo

 

[turbopete]

one of the plus points of MB ownership!!!! amazing what you can buy that you wouldnt have thought possible!

 

[Razoo]

one of the plus points of MB ownership!!!!

Thanks TP, I've been searching for a 'plus point' ever since I purchased the car :lol:

Razoo

 

[turbopete]

glad i could be of help! i get accused by my family of being too negative. maybe i should print this off to prove im a "plus point" kinda guy really!! LOL

 

[Hertfordshire Merx]

They come with the stays on the roof (the part that the sunvisor clips into)

 

[Razoo]

glad i could be of help! i get accused by my family of being too negative. maybe i should print this off to prove im a "plus point" kinda guy really!! LOL

There's nowt wrong with being negative.

I'm a pessimist - which is simply an optimist with experience.

If you always expect the worst to happen, and it does, then because it's what you predicted you are neither surprised nor upset.

On the other hand, if something actually goes right for you, then you can revel in an unexpected moment of euphoria - before the next thing goes wrong and brings you back down to earth.

You know it makes sense :lol:

Albert King, Bad Luck Blues - "If it wasn't for bad luck, I wouldn't have no luck at all" (other versions are available)

Razoo

 

[turbopete]

There's nowt wrong with being negative.

I'm a pessimist - which is simply an optimist with experience.



Albert King, Bad Luck Blues - "If it wasn't for bad luck, I wouldn't have no luck at all" (other versions are available)

Razoo

in my life, that is only too true!!!