Newbie with wiper conundrum

[Robert Hood]

Hello,

I have a 2002, S210 diesel estate car with the 2 ltr engine. The car runs nicely and regularly returns over 50 mpg. However, when I bought the car in 2017 I noticed that the intermittent wiper option on the stalk didn't work properly. It just acted as though I'd set the stalk to normal wiper usage, i.e. continuous slow wipes (as opposed to the fast wipe option).

Yesterday it occurred to me to search the various MB forums to see if anyone else had come across this problem with my model, and on here I found that someone else had. They said they found that by unplugging the sensor that sits just behind the rear view mirror inside the windscreen, the intermittent wipe option on the stalk works correctly.

So this morning I've been out to the car, removed the cover from the sensor, unplugged the sensor, put the cover back on, then started the car and tried the intermittent wiper option. Guess what? It works!! However, I don't know how to speed up or slow down the frequency of the wipes per minute, so I thought I'd ask if anyone here knows whether it's possible to do this or not.

The stupid thing is of course that my wife's cheap old Ford Focus has a twist control on the dedicated wiper stalk that allows her to adjust the frequency of the intermittent wipes whenever she wants. It would be great if the MB engineers had fitted something similar, instead of going for the expensive and unreliable rain sensor they fitted instead. Ho hum, never mind, rant over.

Anyway, if anyone knows how to adjust the intermittent wiper frequency I'd be grateful if you'd let me know how it's done.

Many thanks,

 

[Flyinspanner]

The sensor may be knackered. (Star should be able to diagnose)

The sensor should ‘see’ when screen is clear, and stop wipers, then when rain spots hit a certain level of “droplets/light obscuration” the wipers switch on.

You’re just going to have to twiddle the switch when you want!

 

[Srdl]

I really like the expensive rain sensors and they have always worked just as I want them to 90% of the time. I presume the unreliable bit comes with the 17 years it’s been in your car.

Welcome to the forum, by the way!

 

[LostKiwi]

As above the wipers are designed to be automatic so disconnecting the sensor simply makes them 'dumb' wipers and they default to a fixed speed. All you need do is replace the sensor....

 

[Robert Hood]

Thank you all for your replies. I think I'll just leave it as it is for now. I'm happy with it working as a normal intermittent wiper, and I don't want to spend any more money on it than I have to.

 

[Blobcat]

Hello and welcome, I'd also lubricate the mechanism, pictures dead unfortunately but procedure here

 

[Frontstep]

Definitely as above lift the cover and grease the mechanism I do mine when I change the blade.