C5 faulty rain sensor

[Howie55]

Hope someone can help. I have a 59 C5 Exclusive and the wipers will only work on intermittent when it is raining. The strange thing is, when it is dry, they work fine on all positions! I went out yesterday whilst the weather was showery and as soon as the windscreen dried, the wipers worked as they should but once I hit spray from the vehicle in front they went to intermittent only!
Any advice would be appreciated, thanks

[SaabC5]

Is this in auto mode or if you manually select the speed?

[Howie55]

all, it doesn't matter which position the arm is in, once rain hits the screen it goes into intermittent mode

[vborovic]

I fail to understand what do you mean by "intermittent mode"?

[Howie55]

when there is a delay between sweeps of the windscreen!

[vborovic]

Ok, let's start with the basics ... when you start the car, and press the wiper stick down, will you get the message Automatic wiping active? If so, will the wipers start working if you pour some water over the windscreen sensor or if you drive it outside if it is raining? If you then put the wiper stalk to position 1, will you get a Automatic wiping active disabled (or similar) message? Are the wipers functioning normally on the positions 1-3 (only the speed is different, of course the wiping is intermittent)?

[Howie55]

If the stalk is down (auto) and it rains - nothing happens, move it to the 'off'position and back to the auto position it sweeps the screen but only in intermittently. I can then move it to any other 'on' position and it will only operate intermittently. When it stops raining it operates in all the up positions as normal - intermittent, normal and fast. Strange quirk of Citroen!

[MikeT]

If the stalk is left in the auto setting when engine switched off, it won't re-activate on restart. You have to switch it to manual then back to auto which sounds like what you describe. Intermittent speed is according to rainfall intensity and vehicle speed.

[Howie55]

Yes Mike, I know that but that is not the problem - please read the first post!

[vborovic]

Have the wipers worked "normally" before, or is this as described the entire time since you had the car? Also, you didn't mention whether or not you actually get a message confirmation on the instrument panel, after activating/deactivating the automatic wiping?

[myglaren]

Yes Mike, I know that but that is not the problem - please read the first post!

I'm sure the X7s are different to ours Mike. Mine will sometimes work automatically when it starts raining, sometimes not, depending probably on what day it is or the phase of the moon - it's always left in automatic mode.

One rather unscientific approach is to try a BSI reset. Might work, might not. Like a lot of other Citroen things, you never can tell until you try it.

Do the autolights work? They are on a common sensor on the newer cars where ours have discrete sensors.

[Howie55]

When I move the stalk, it says on the panel that the wipers are either activated or de-activated as they should be. The wipers always worked perfect and I have had this car for 5 years. I only noticed this the last couple of times I have been out in the rain.

[bigblackfalco]

Mine doesn't work brilliantly on auto either. It seems to be too slow or too fast. Very rarely does it work at the right pace!
Don't know where the sensor is located, but guessing the location could be the culprit.
I did a bsi reset about a year ago, which seemed to smooth a lot of things out. Maybe it's time for another!

[Hell Razor5543]

Normally the rain sensor is mounted on the rear view mirror mount.

[Stickyfinger]

Mine works really well....I have it on Auto most of the time.....full variable dependant on just a drop or even road splash. If needed I give a quick squirt (single command wipe) and leave the rest to the auto wipe.