Windscreen rain sensor

[MBNuB]

I've just had my windscreen replaced. The guys tested the rain-sensor and the light sensor when they put the new screen in, but the rain sensor now appears not to be working. When I turn the wipers to A, they wipe continually.

Question is: is there something I can check before calling the windscreen boys back, or have they broken something they're going to have to fix?

I know I can whip-off the plastic cover just behind the mirror and expose the light and rain sensors but which one is which, and how can I unclip them to check them out? And how do I check them out?

Thanks in advance.

 

[bigasotonuk]

If the rain sensor was,nt in circuit it would automatically default to a regular intermittent wipe in position A.
I maybe wrong as I have,nt personally come across this but I think the sensor will need to be calibrated via a STAR computer. #
I think you need to call the windscreen people out again.

 

[sixpack]

Rain sensing wipers

Hi Big,


Thats interesting, if the rain sensor is disconnected, it reverts to intermittent wipe. I,ve never been that happy with the rain sensor on my 203, seems to be a bit erratic. If I unplug the sensor, i get int. wipe ?. Is it easy to get to and will it show a fault code ?


Peter

 

[W124W203]

Rain Sensor

A number of years ago when I first got a 51 Plate W 203 I had a problem with intermitant wiper, I took off the sensor connected to the windscreen and cleaned the (eye) checked everything I could and blew out the dust put it back together, after that it has worked fine. I cannot remember just how I took it apart but it wasnt difficult.

 

[bigasotonuk]

Hi Big,


Thats interesting, if the rain sensor is disconnected, it reverts to intermittent wipe. I,ve never been that happy with the rain sensor on my 203, seems to be a bit erratic. If I unplug the sensor, i get int. wipe ?. Is it easy to get to and will it show a fault code ?


Peter

Well on mine i noticed the wipers were not reacting to rain, but instead were wiping at regular intervals, after trawling old threads i found confirmation that when the sensor goes open circuit it does indeed revert to intermittent.
This was confirmed when i took my mirror down and found the rain sensor unplugged.

 

[MBNuB]

Many thanks for your replies, folks.
My car obviously reads this forum, too! I was out all day Saturday with friends and was the nominated passenger on the way home. When I got back behind the wheel in the drizzle yesterday morning, the wipers were back to their intermittent best!
I don't know if they just needed to stretch their legs after the disturbance of a new screen or if there was just some new-screen muck left over the sensor, but all is resolved now.