Auto dim RVM/ wing mirrors test

[stringbag]

Does anyone know how to test the auto dimming wing mirrors on a C43? My Rear view mirror auto dims, and I have seen it turn slightly darker, but have never noticed the wing mirrors doing anything. How do you check, and what are they supposed to do? How do they work anyway?
The RVM has a small 'eye' on it, which I assume is a light sensor.
(The glass in one of my wing mirrors has a slight crack in in and I want to see if it still works!)
I saw the thread about one leaking - do they contain fluid? why?

Thanks
stringbag
nb the wing mirrors are folding ones.

 

[NW_Merc]

Check it by shining a torch on them perhaps? Or an led type light

 

[Shude]

The only sensors for dimming mirrors are in the RVM, the door mirrors (usually just the driver's mirror) will dim at the same time.

Put a finger over the sensor on the forward-facing part of the RVM and shine a bright torch at the backward facing sensor on the glass-part of the mirror, the RVM should pretty much instantly go black or very dark green, the door mirrors should dim at the same time to either black or a very dark goldish colour IIRC.

You'll need a key in the ignition and have it turned a few notches (maybe not engine running) to get this to work, if the dimming mirror worked without the keys in the car's battery would be flat every morning

 

[richard]

The only sensors for dimming mirrors are in the RVM, the door mirrors (usually just the driver's mirror) will dim at the same time.

You could have the interior dimming mirror , and not have the drivers external dimming mirror - if you look at the drivers mirror, it should have a black plastic surround to the lens if it is the dimming variety.

You'll need a key in the ignition and have it turned a few notches (maybe not engine running) to get this to work, if the dimming mirror worked without the keys in the car's battery would be flat every morning

Also, you must not be in reverse !


R

 

[fuzzer]

I dunno about you guys , but i really hate the exterior dimming mirror . Much better with a polarised blue one than the dimming exterior.

 

[stringbag]

Checked it just now - There is a sensor on the front windscreen just in front of the mirror, and a small sensor in the top right hand corner of the glass on the rear view mirror itself. Tested as described above and all works ok.:bannana: Only the drivers side wing mirror dimms, and it goes a sort of goldy green.
Still don't know how they work - they don't actually move at all.
Thanks
Stringbag

 

[fuzzer]

Checked it just now - There is a sensor on the front windscreen just in front of the mirror, and a small sensor in the top right hand corner of the glass on the rear view mirror itself. Tested as described above and all works ok.:bannana: Only the drivers side wing mirror dimms, and it goes a sort of goldy green.
Still don't know how they work - they don't actually move at all.
Thanks
Stringbag

Crystals in the glass change colour when an electrical currant is passed over them.

 

[Shude]

Checked it just now - There is a sensor on the front windscreen just in front of the mirror, and a small sensor in the top right hand corner of the glass on the rear view mirror itself. Tested as described above and all works ok.:bannana: Only the drivers side wing mirror dimms, and it goes a sort of goldy green.

The sensors for your RVM are both built into the mirror itself, one on the glass (which you mention) and one on the back of the mirror housing, facing the front of the car. If your car is a C43/any W202 then the sensor on the windscreen is for something else, most likely auto-wipers.

 

[Dieselman]

I dunno about you guys , but i really hate the exterior dimming mirror . Much better with a polarised blue one than the dimming exterior.

Always one for a joke, eh Fuzzer.

Maybe the BMW dipping mirrors don't work as well as the real Mcoy.

 

[fuzzer]

Always one for a joke, eh Fuzzer.

Maybe the BMW dipping mirrors don't work as well as the real Mcoy.

lol nooo im being serious. I don't order my bmw's with the dipping exterior mirror cause its crap.

All the mercedes have come with them since the w210 i had. I much prefered the blue polarised one on the w202.

 

[stringbag]

Just looked again. You are absolutely correct - there is a sensor on the rear part of the rear view mirror as well. The one in the windscreen is for the auto wipers. I just covered the whole windscreen with a sheet, so covered the RVM sensor by accident! Still, it works, so that it all that matters.
Thanks
Stringbag