Twizy Rain Light Sensor Fault

Whoa, that sounds familiar! I have a Twizy too, and I had almost the exact same problem last year. The lights kept turning on and off randomly, and the wipers were doing their own thing. I was pulling my hair out trying to figure it out! Did you check the windshield near the sensor?

I've looked at the windshield near the rain-light sensor, but only quickly. What should I be looking for? Is there a specific problem I should be seeking?

Yes! Okay, so on mine, tiny bubbles had formed under the gel pad where the sensor sits against the glass. They were almost impossible to see at first glance. The workshop told me that the bubbles were messing with the sensor's ability to detect rain properly. They replaced the gel pad, and that fixed everything. Maybe that's what's happening with yours? I would go to the workshop, and let them take a look.

Thanks for the help. I checked the windshield carefully and found tiny bubbles under the gel pad, just like you said. I went to the workshop, and they replaced the gel pad for 62€. That fixed everything, the rain-light sensor works, and all the problems are gone. Your help saved me a lot of time and money.