W210 auto wiper annoyance

[automaniac]

The auto wiper function on my w210 is driving me nuts It never seems to work properly, when I switch it on, off it goes and never stops even if the screen is dry, but if I turn it off and back on, it will do the one sweep and then wait untill the screen gets wet and off it goes again. Replacing The wiper blade has made no difference, however the screen is covered in fine scratches from the wiper action over the years, is it possible that the rain sensor may be mistaking these scratches for rain?? or does the sensor fail causing this problem??
Or is the system just a pile of doo doo, and nothing can be done about it??.
I would prefer a staightforward intermittant wipe than this system, I used to own a peugeot with auto wipers and that system worked perfectly, which is yet another reason that buying this upmarket car has dissapointed me in so many ways

 

[richard]

The auto wiper function on my w210 is driving me nuts

Sounds like you either need a new rainsensor, it just needs recalibrating to the windscreen. As a new one needs recalibrating in anycase, you have to get a dealer or a indi with star diagnosis machine to check/replace it

I find it works perfectly for me (on all 3 cars)

You could disconnect the rain sesnor connection (back of rainsensor) and it will revert to intermittent wipe. - you can;t do that if you have a combined rain/light sensor like my A class does. Theres a mixture on older cars, and I don't know what yours may have

Cheers
Richard

 

[television]

I polish my own windscreens with a glass polish, it takes away all wiper marks,and they are not good when its raining in the dark. You do need the special polish and the polisher and foam head, Makes them like new .

Malcolm

 

[automaniac]

Thanks for your replies, I might just diconnect the system and have ordinary intermittant wipe. After shelling out nearly £600 last month to a stealership for a new ignition barrel , I dont really want to see them again for a while!!!

 

[clegsr]

My W210 exhibited almost exactly the same symptons with the auto rain sensor:

When it started raining, however slightly, it would start wiping and then not stop until I switched it off again. Then if I stopped the ignition and then restarted the engine with the auto wiper on it would do one wipe and wait until it started raining again, or sometimes it would be OK and work properly.

I have just changed the wiper blade(£17) with a genuine MB spare and it seems to have fixed the problem.

I am not sure how the rain sensor works - or what it is actually sensing but perhaps cleaning/polishing the glass might help.