RAIN SENSITIVE WIPERS 320 CDi

[PAUL GARDNER]

Can anyone advise of the best 'fix' for Rain Sensitive wipers which do not work - how do you check for fault ? and where is the sensor located ? - Is it OK to assume that if the sensor works [yet to be proven] it must be the wiper motor ! - The wipers work on two speeds but the first setting for the 'sensetive' merely activates the wipers onto the continuous first speed - I am not fussy about the sensitive setting as I suspect it is a troublesome feature but would like an 'intermittant' facility - can this be done or is it a question of a motor replacement - Thanks - All ideas/alternatives appreciated - Paul

 

[television]

The fault will not be the motor, that is for sure, the speed sensitive bit is behind the mirror housing that covers the blue Spot on the screen at the top. that area around the spot must be clean

whitenemesis knows these things well, I hope that he sees the post

 

[stevesey]

My wiper blade has developed the habit of slipping down the "hook" on the wiper arm by about about 1in, so it doesn't clear the blue spot properly and wipers stay on in auto mode. It's just stopped raining here and sun is out, so I'm about to see if I can fix the "barb" bit should stop this. Could be something similar in your case.

 

[stevesey]

Sorted - last person to change the wiper blade didn't use the correct adaptor bit so there was nothing positively locating the blade in the hook - have used some masking tape to generate a force fit, can't be seen and will do until a new wiper blade is needed.

Years ago I'd always keep the spare adaptors after changing blades, "just in case", of course I never needed them so gave up.

Anyway Paul I hope yours turns out to be something simple like this. Do the wipers come on at normal speed even if the screen is dry (and clean)?

 

[whitenemesis]

The rain sensor is usually located adjacent to, or is combined with, the light sensor that switches on the headlights. This is behind the RVM, attached to the inside of the windscreen.
Please excuse the obvious question but do you have rain sensor wipers? Did they work before?
On my car there are three wiper setings, I,intermitent (sensor), II, constant single speed and III, constant double speed. I always leave it on I and let the sensor set the speed which will range from variable intermitent through to constant double .

To check the sensor, with the ignition on, set the switch to I and spray the sensor area with a plant mister. They shoud spring to life. On earlier models switching the ignition on whilst the wiper switch is on I will give a single wipe, even on a dry screen.

The best test is to get hooked up to a STAR diagnosis kit and read off the sensor state. Sensors will fail safe and give a constant wiper action.

 

[television]

You must have heard me calling whitenemesis

 

[whitenemesis]

LOL

Nearly a clean sweep on the new posts there Malcolm!

 

[television]

LOL

Nearly a clean sweep on the new posts there Malcolm!

Why did you spoil it

 

[robbo]

I've unplugged my rain sensor and position 1 is now a regular intermittent setting. Much better if you ask me.

 

[whitenemesis]

But not variable....

As you might expect to find on even on a C*rsa!

Unbelievable MB don't have variable wipe as standard

 

[robbo]

Yeah, but thats much better than the rain sensor, which either doesn't wipe enough or wipes like mad when there is light drizzle so the wipers scrape across the screen and drive you mad.

pointless feature if you ask me.

 

[whitenemesis]

Perhaps you need to get the sensor re-adapted to the screen?

I find mine very good and wouldn't be without it.

 

[Geezer]

I find mine very good and wouldn't be without it.

Me too. Excellent feature IMO.

 

[television]

Me too. Excellent feature IMO.

Its interesting how Rain X can make them work differently

 

[whitenemesis]

The system wasn't designed for use with Rain-X

 

[television]

The system wasn't designed for use with Rain-X

I tried it and the system is nowhere near as sensitive , I will remove it and just keep it on the side windows

 

[M6AJJ]

The sensors can be recaibrated by MB.

 

[PAUL GARDNER]

This is a 2003 CDi Avengarde which I have had for 4 months and the rain sensor wipers have never worked - so I assumed it had this type of wipers - Now I know and can confirm there is a blue spot - and the blade sweeps it clean - and no amount of water triggers it - what is the quick fix ? - or alternative
I am keen on the idea that the sensor can be disconected and therefore the 1st position becomes a normal intermittent - but how do you do this - is it a case of revealing the wiring and unplugging the sensor ? somewhere inside at the top of the screen - or does it need the curcuit maintained ? - or is it a rewiring job somewhere else in the bowels of the car - Thanks for everyone's help - Paul

 

[PAUL GARDNER]

Will you look at my longer reply as I am interested in how you disconect the sensor and therefore make the 1st setting normal intermittent - Thanks - Paul

 

[television]

Will you look at my longer reply as I am interested in how you disconect the sensor and therefore make the 1st setting normal intermittent - Thanks - Paul

I do not think that you can make it intermittent as the circuitry to do this will not be there, unless anyone else knows better on this