Mister Bean

Howdy folks. My mother owns a 240Z, though I can't remember which year it is. Like the title says, the wipers only work when it isn't raining, so if it's dry out they work just fine, but then as soon as it starts raining they stop. Sometimes even just using the washers will make them stop. Snow will also stop them. She has tried taking it in to a couple mechanics but none of them have had any success with it. Including an "electrical specialist" that she took it to. So I thought I'd give it a try since it's her only form of transportation at the moment. I've spent some time looking through the archives here and haven't found anything similar. Any thoughts?