power steering problem

Haha once again, my g/f has a problem with her power steering. It is always been fine, but whenever she hits a puddle or a pot whole in the rain, her power steering will go out and sometime her battery light will come on, then after a couple of seconds the power steering is fine and the battery light turns back off, anyone else heard of something like this?
Thanks ya!

The answer is : the belt is slipping. When it is dry there is enough friction to keep everything turning, but if the belt is worn and/or the idler is not giving it the right amount of tension, then as soon as it gets wet it will slip.