Unfortunately, a plastic bag over the controls isn't always enough. Mind you, getting caught in a torrential thunderstorm doesn't help matters! My
ECV died 3/4 way round the World Showcase and that was it. Turns out there was a reset button that I wasn't told about, so I may have been able to get it going again. I was wearing a poncho, as well ...
It's possible that you need a full ECV rain poncho - one which covers all of you
and the console
and your hands!