Rain Sensing wipers

[shaunevans1409]

Hi all, a strange thing happened this evening with the rain sensing wipers on my 2004 W211 320 Cdi. The wipers had been set to position 1 for some time, but didn't need to work as there was no rain, only an occasional very fine mist. Then I noticed that the wipers operated once when I accelerated quickly! Kept trying & sure enough, slow acceleration - no flick. Put your foot down & Hey Presto - On they'd come! This happened many times, so wasn't a fluke.

Am I missing something obvious here? Your thoughts as always would be appreciated.

Cheers..............Shaun.

 

[darrenb1707]

I've had that a few time with my mine too.

I've always suspected it was to do with moisture in the air that you dont really see a 'rain'. The faster you go, the more it accumulates on the sensor which is really just a very small dot on the top of the windscreen anyway. Probably more likely to happen once the interior has warmed up and cold water vapour condenses on the warm(ish) windscreen glass.

I cant think of anything else it could be although I'm sure there may be others on the forum who my be able to offer a more technical explanation.

 

[television]

We had a thread yesterday on the odd behavior of the wipers, I would ignore it for now, mine do funny things sometimes, as Darren said the fine rain or moisture can upset them, this is why they do not work with rainX on the screen.

See how they go

 

[shaunevans1409]

Thanks guys, will do..........................Shaun.

 

[TheScrapman]

they do not work with rainX on the screen.

Ah there we go, thanks!
Another Benz fault fixed for me!
Now all I need to do is work out to get the rain-x off!

 

[television]

Ah there we go, thanks!
Another Benz fault fixed for me!
Now all I need to do is work out to get the rain-x off!

What happens is with rainX is that it turns the rain drops into tiny microbes to small to put the sensor out of focus.

A wipe over with petrol or meths should do it, even vinegar