I have a 2008 Ducato and am having intermittent problems with wet electrics. I hit some water on the main road at appox 70 km's and have been having problems since then. The motor will not turn off. Turn the key off, the dash lights go off but the motor still runs. Have to wriggle the key off and on to stop the motor. The motor doesn't always start as previous. Now the electric fan is turning on and off by itself even when the ignition is turned off. Probably water in the electrics but any suggestions on where to start

Yep, that's probably it, but then again it may not be. Is there a Ducato forum you could post your enquiry on?