I have a '02 Taurus. Over the summer had the same issue-water on the front passangers side. Then last week, my heat started to slow down and stopped working. I took it to the dealer( I live in Boston and really can't go without heat in the car!
...anyways---they had to replace the blower motor and resistor along with the cowl and weatherstrip. They said it corroded the motor due to the water leak. Mine was not covered under warranty---I would get it to the dealer soon--hopefully yours is still covered!
Hope this helps....Good luck