Hi Everyone, I have a 1999 Mercury Marquie, My problem is the back floor well on the right side fills up with water every time it rains, there is no sign of water running down the window on that side but there is a heat and air duct that emptys out into the floor well. This only happens when it rains and the heater is on!. I have pulled about a gallon of water out of the well. the air duct is above the well. the water does not drain out, it only fills up.........thanks for any help How does water get into the duct? The rest of the car is dry!

 

I have had the same problem with the wifes 95. Took forever to figure it out but is a simple fix. Under the hood next to the windshield there are two drains one on each side. They drain down to the wheel wells and once they become blocked the overflowruns directly into the passenger compartment and back to the rear. You will need toremove the plastic housingcovering the drains which have a screen on top of them(six or eight screws) the problem is not the screens being clogged but if you follow the drains youwill find someting blocking them at the bottomof the wheel where it drains over top the tire. Hope this helps keep you dry.

 

Thanks opsman. I came on here looking for the same advice on my 1997 Sable; I was worried that the bottom was rusted out. It's been getting progressively worse, and when we came back from vacation, there were 2" of standing water in there. I'll try your solution.