pfphipps

99 SLK230--had it since new. The driver's rear view mirror has turned yellow. It started out looking like the other mirrors but in the past few months, it has turned yellow and seems to be getting worse. Anyone else have this problem?

maninblack

not on mercedes , but for bmw , it the element for the heated mirror turns bad , maybe the same

pfphipps

Interesting. I will check that as well. I never really saw the big advantage of the dimming mirror especially since the right hand size does not have it anyway. Maybe my eyes are not that sensitive any more.

scorchie

It sounds like the dimming part of your mirror has failed. This is usually due to an electrical problem... so if you replace the mirror glass, you may end up with the same effect.

-s-

DickB

Can't imagine what kind of electrical problem would cause this; it's a simple heater in there. My mirror turned blochy yellow and replacement of the glass with its integrated heater was the answer. No problems after many months. I think it's the glass and replacement is the cure.

scorchie

I'm glad it worked out for you, but your single case does not constitute a good sample set.

It's not just a simple heater in there, there's a liquid crystal for use with the autodimming system. Sometimes the electrolyte is contaminated; other times overcurrent to the autodimming can cause yellowness. The overcurrent is what you want to beware of.

The heater may cause a problem, but I've seen W210 mirrors get REALLY HOT without causing any problems. I've seen nearly as many mirrors get ruined because of overcurrent to the autodimming (Steve does a lot of experimenting for research purposes).

-s-

pfphipps

What causes the over current problem? Will it correct itself if the heating is disconnected? Here in New Mexico, I have not seen much of a need for heating the mirror anyway.

I see what appears to be a sensor in the corner of the inside mirror but where is the electronics that controls the outside mirror dimming and heating? Any good words on troubleshooting, any electrial diagrams or hints on what can and cannot be repaired would be appreciated.

At first I thought it was in full dim mode but I notice at night when the regular rear view mirror inside the car dims, the outside mirror is very yellow compared to the view in inside mirror.

DickB

I stand corrected.

I had assumed that a heating element of some kind was used to dim the mirror. I think I was wrong. Investigating more closely I find that the mirror has both a heating element to clear ice and snow (triggered by a thermo sensor in the mirror) and a voltage control for dimming the mirror (not sure of the mechanism – LCD?). The nominal dimming voltage is 0-1.5 volts. If the control circuitry malfunctioned and fed a higher voltage to the mirror, that could cause an over current situation.

DickB

Now that I've studied info from alldatadiy.com, here is what I think I know:

The sensor in the outside mirror is a temperature sensor for the heating element to clear ice and snow. it is activated at 15 degrees C and deactivated at 25 degrees C.

Dimming is controlled by the inside mirror, which sends a voltage signal of 0-1.5 volts to the left outside mirror.

I'd still bet that if you're seeing yellow in the theoutside mirror the problem is with the mirror.

pfphipps

More information than I have ever had before! Does anyone know the procedure for taking the outside mirror apart? This seems to give a C class mirror information but is it the same for the E?

https://mbworld.org/forums/showthrea...or+replacement

As far as the mirror heating, 15 C seems high for where it comes one but maybe I do not understand that part living where the humidity is sometimes under 5%. On the other hand, 15 F would seem way too low.

DickB

1 Fold the outside mirror forward
2 Tip the top edge of the mirror glass to the outside
3 Using a screwdriver, push the retaining spring (1) upward and remove the mirror glass from the drive
4 Disconnect connector (2)
5 Install in the reverse order