I do not have this option, although I have a lot more other. What part do I need to buy? How do I need to connect it? Any documentation available? ML 350, 2008
Thank you.

You will need a rain sensor and some cleaning materials.

Peel the light sensor off the glass, remove gel on glass and then attach the new sensor.

Check the wiring and control panel connections.

Perform some simple coding with the diagnostic.

In some cases you may need a new overhead control panel.

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And where can I find some docs about this?

There are none :-(

The part number you need is A164 820 30 85 (ML after chassis nr 212139 dec 2006)

Being a 2008 you should be OK on the overhead control panel.

When you have removed the old rain sensor (EDIT: or the light sensor in your case), remember to clear out all the gunk properly before installing new one. Also, you will need the Rain Sensor enabling in the OCP and possibly CGW/EIS, and then the 'initial startup' sequence done - but Mercedes dealer will have done the latter whenever he has replaced windscreens or rain sensors and should be able to work out what to do if you tell him the above.

Richard

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Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

So, do you think that I have already rain sensor but is not working? How can I check if I have it? Where is it located? Do I need to have windshield with a special clear window for it? Or all the windshields are like this? Can I find some manuals or pictures with these, or do I need to go directly to the representative?
Thanks.

Its attached behind the inside mirror to the windscreen (at the top)

There is a "just light sensor" and a "combined rain/light sensor". All MLs have one of those. (The light sensor is what controls auto headlights and some other stuff)

The plastic cover clips off (pull from low end carefully) revealing the black plastic sensor and wiring. Theres a part number on the sensor, post that here and i'll tell you what it is.

A new rain sensor has to be calibrated to the windscreen by the dealer (with star diagnosis). If car only had light sensor and you are installing rain/light sensor, the OCP (overhead control panel where it plugs into) needs to be told there is a rain/light sensor, and then calibration done.

Cheers

Richard

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

On the label:
164 820 3085
00 6066 08
SW: 500552 HW: 1806

It appears to be both rain and light sensor.

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www.benzmodz.com .... putting the Me into Mercedes.

So, why is not working? Where do I need to check the settings? Is there an article for this? Thanks.

I've often see people think their rain sensor doesnt work because they arent testing it properly (normally because they have tested with door open)

a) You put the stalk on the intermediate position (some cars have 2 such positions), but start with the first position
b) If when driving along at a normal speed it wipes at exactly the same intervals then it is either not present or the car thinks it is not present
c) if the intervals are not equal then it is at least basically working
d) It behaves differently when stationary (in that even if wipers are on they switch to intermittent)
e) It does not function if a front door (maybee just drivers door) is open so as not to wet the driver when getting in / out (so you can not test by squirting water on it if door open)

You can thus test it by engine running, doors shut (have window shut also), and squirting water on on it.

What goes wrong sometimes is that the windscreen is replaced and the sensor is not re-calibrate.

The sensor can get 'triggered' when driving through a forest where the light is coming through in 'beams', and iced up windscreens reduce functionality also.

The only way of really diagnosising and of re-calibrating is with Star Diagnosis (sorry)

History:
Cars used to have only 1 intermittent position, and many people found it was not quite to their liking, so MB introduced two positions, one which wipes more often. My 07 ML has the two postion, but an 05 ML I looked at the other day only had 1 position. I prefer the 2nd position (i.e more wiping).


Richard

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk