Mercedes C180, issue with mirror indicator

[Triplesilk]

Hi all, I wonder is anyone can give me a steer on what to do. If the answer is that I have to take the car to a dealer then fair enough, but I like to try to fix things myself as far as I can first so I'm keen to try anything that I can.

My car is a 2002 C180 estate. The passenger side wing mirror indicator no longer works, and I get a warning on this on the internal display panel.

There was a bit of damage on the plastic cover of the bulbs, but nothing much, though it may be that a slight bang caused the issue. Anyway, I bought a new part (which is the whole plastic unit, with the four bulb inside) and fitted that. This does not fixed the problem though.

I notice that the inside controller where I can change the angle of the mirror glass when sitting at the driver's seat doesn't work either, though the whole mirror unit can be closed or opened automatically from inside the car.

When I fitted the new part I had a look at the wiring and nothing obvious was wrong. When the mirror cover gets pushed back in the connection is made on contact. I can't be 100% sure that this is being lined up but it seems like it is, but in any case this may not (?) effect the mirror angle control so it made me think that something else is the issue.

Anyway, any kind of steer would be great!

 

[whitenemesis]

You checked the wiring around the point where the mirror folds? This is a common issue and more often than not only one wire in the loom fractures, affecting that particular function

 

[Triplesilk]

You checked the wiring around the point where the mirror folds? This is a common issue and more often than not only one wire in the loom fractures, affecting that particular function

Thanks, I thought I did not now I know how to get the cover off I'll have to have another look. You mean that I want to make sure the mirror unit is as flat as it can be (ie tucked in) and I just check that wires look to be feeding through?

 

[markjay]

The issue is almost cerainly due to one or more disconnected wires around the area where the wires flex each time the wing mirror is folded or unfolded.

The difficulty is that a wire can have an internal disconnection while the external insulating layer is still intact, making it very very difficult to identify the faulty wire(s).

If you are lucky you might be able to see actual damage to the insulation, but otherwise it can be difficult to spot the faulty wire or the exact location of the fault.

If the issue is intermittent then you can try wrigling the wires one at a time and see which one is causing the error message to come up.

A dealer would have no issue in resolving this simply because the official solution involves replacing of the entire wiring loom - which wi obviously cure the problem, but will be more expensive in terms of parts and labour.

 

[Triplesilk]

Thanks a lot. I'll have a look and hope I missed something, otherwise it looks like I have to cough up a load of cash :-(

 

[grumpyoldgit]

Don't know if these diagrams will help you, but the direction indicator repeaters are numbers 43 & 44 in the first diagram and the wires to the repeater are Brown/Yellow and Black/Yellow on both sides. Hope it helps trace any break that there may be.

To view larger images, click on them (this will open them in Photobucket) and click on the magnifying glass icon with a '+' symbol in the centre.

 

[Triplesilk]

Thanks man, it does look scary but I only need to focus on part of it I guess and the colour-coding may help also. When it's nice and light tomorrow I'll have a good look. I'm toying with removing more than just the wing-mirror cover, as I may do more harm than good. It does seem likely that the fault wasn't internal though as has been said so I may see something if I look hard enough....fingers crossed anyway ;-)

 

[Triplesilk]

Just to follow up, I took things apart and all wires look OK. I tested the clip that the bulb connects to, when it was supposed to be on, and get zero volts with a multi-meter. So I'm resigned to having it fixed and coughing up lots of cash :-(

Thanks to everyone for the help.

 

[whitenemesis]

Did you check whilst wiggling the wires?

How about checking the wires in the door hinge bellows?

 

[Triplesilk]

I had a good look and all wires looked solid - and did wiggle around a fair bit. I really couldn't get anything above zero on the multimeter so it seemed bad :-(

One thing I didn't do was take the whole thing off the car, mainly as it needed a weird alan key size/shape that I didn't have, but it got to the stage where I kind of figured that even if I could see some damage deep inside the car I probably wouldn't be able to fix it myself. I really hate to admit defeat though but I may have to!

 

[Triplesilk]

Just to close this off, in case anyone sees the thread in a search etc.....

...I took the car in and the guy said that all the wires were broken right by the motor. It beats me why I couldn't see this, but I didn't strip everything away I guess. Plus, unless simple wire connectors would work it would be a hassle for me to fix anyway. The plastic bulb part that I replaced was dented with a hole, so maybe a sudden bang caused it.

The charge was £55 (including vat at 20%), which seems fair enough to me.