Hi, I have a BMW 6 series (635d). The wipers have stopped working we have changed the relay and checked fuses and even changed the stalk all are ok. They were working as and when they felt like it and then we noticed that the drivers sided was filled with water due to a blocked drain (common). We dried the area out and they were working fine. However, now they have stopped working again completely the wipers cannot even be moved they are jammed solid. Any ideas?

The area we found before is all dry, we are really confused