Help - Rain sensor for wiper ?

[14Ben]

Hi everyone,

Just a quick one . . . I've just noticed that the rain sensor for my wiper isnt operating as it should be.

Instead of cleaning the screen when required, it jumps straight to the medium speed which means I cant use the slowest speed.

HOWEVER, when I unplug the small plug to the mini black box just above my rear view mirror (which i assume controls the sensor) it allows me to select the slowest speed, but it isnt rain sensitive.

Does this mean I need a new sensor or is there a simpler solution. I wasnt sure it that little black box above the rear view mirror functioned as anything else either, and what would happen if i left it unplugged ?

Long shot i know but if it does need replacing any ideas on cost ?

Thanks so much,

Ben

 

[shorty]

The black box controls the wiper and light sensor functions .

 

[14Ben]

Shorty - What light sensor ? ? ?

 

[whitenemesis]

Depending on the model year the sensor could be just the rain sensor, with a separate light sensor next to it or the later version which is the combined rain and light sensor (RLS).

If the latter and you unplug it your car will think it permanently night and you would get a malfunction indicator in the cluster, along with an annoying beep..

These sensors are not expensive the RLS is approx £40 I would expect the separate rain sensor to be similar in price

 

[14Ben]

Thanks White - its a 2002 W208 model but im guessing its just the rain sensor as I've never noticed the lights automatically coming on, unless there is something I need to do to active that setting ?

The black box looks too big just to be a rain sensor though, is it possible I do have the rain and light sensor but it hasnt been set up properly with STAR ?

Thanks

 

[Dieselman]

Is the screen really clean where the sensor looks through.? Any residue can trip the sensor into seeing a rainy screen.

 

[c240yaz]

I have a similar prob on my 2001 C240. Where is the sensor on mine and how do I fix ?

 

[Druk]

With a view to overriding the indecisive sensor on mine (I was told it would revert to default 6sec delay) I put a piece of black duct tape over the sensor. That didn't have the desired result but when I took the tape off the sensor had fixed itself and remains fixed. ?????????. Not saying it will work for you but a cheap repair if it does.
Don't ask me to explain how though.

 

[whitenemesis]

Thanks White - its a 2002 W208 model but im guessing its just the rain sensor as I've never noticed the lights automatically coming on, unless there is something I need to do to active that setting ?

The black box looks too big just to be a rain sensor though, is it possible I do have the rain and light sensor but it hasnt been set up properly with STAR ?

Thanks

Actually I don't think your model has auto-lights, so no light sensor, just rain..

 

[smiddyboy1]

These sensors are not expensive the RLS is approx £40 I would expect the separate rain sensor to be similar in price

IIRC the rain sensor for the pre-facelift W203 is around the £100 mark, I look at a retrofit, but found out I needed a new screen, much better option is the RLS, but requires a little rewiring.. could have been your post I read...