C4 Cactus wipers work when dry but go nuts when it rains

[Liambp]

The front wipers on my 2020 model C4 Cactus have been acting up for several months. They turn on and off at random and they often stop half way. I had the car serviced recently and the garage found nothing wrong. The wipers worked perfectly when they tried them.

It took me a while to figure out what is going on - the wipers work perfectly when it is dry but when it is raining the wipers go bananas.

I guess that water is leaking onto some electronic control board but I don't know where to look for it. Any ideas?

[GiveMeABreak]

These only have a single motor unit, not the separate wiper motors with ECUs, so either there is a problem with the motor wiring or the comms control unit.

Try a BSI Reset / Battery Disconnect / Reconnect Procedure as it doesn't cost anything.

[Liambp]

Thank you for the reply. I'm going to try that disconnect procedure and see what happens.

[GiveMeABreak]

Also, I forgot to mention, if you have auto rain sensing wipers, the sensor area may be obscured with grease or grime.

Use a good Windscreen cleaner focussing on the area of the sensor and don't use Rainex or any other repellent. Reason being is Rainex causes water to dissipate rapidly over the windscreen and this can fool the rain sensor to thinking the rain is heavier than it actually is.

But I would certainly give the hole windscreen and the wiper blades a seriously good de-grease.