2000 Caravan wipers won't work

[charnock]

We recently had our wipers frozen up in the ice storm, I thought they were unstuck, but when I turned on the wipers, the right one just lurched a little bit, I turned the wipers off, went out, scraped off some more ice and tried again, it still wouldn't work, but then it lurched up once, went completely off the window and hit the other wiper on the way back down. Now neither of the wipers will move, they both just jerk a little bit when I turn them on. I've heard that the wiper rod can dislocate from the wiper motor, does anyone know about this?