First of all, I know some folks have started threads on this and they have been extremely helpful. I'd especially like to thank Durasel for his help. I narrowed down the pesky wet passenger side floor to two different issues. The first is if you haven't had the rain hat extension installed, you will get water through the weep hole under the dash above where the passenger's right foot would be on the carpet. That's the issue where the blower motor usually ends up corroded and where most folks bite off on the windshield cowling as the cause. Water gets in through the cabin air filter opening. There is a well documented Ford procedure to fix this.
A separate issue is the issue my 2004 Taurus SE had. Water gets in the cabin where the Air Conditioning drain meets the firewall. The drain housing meets the firewall in the front of the passenger floorboard under the dash. (picture attached) That drain is horizontal, so some of the water actually drips back down the
spout and back through the firewall, which is only "sealed" by a thin piece of foam insulation. It's like when you try and pour water out of a coffee mug....you know how the water runs back down the side of the cup as you pour? That's what the water does out of the AC drain and it comes right back into the cabin on the passenger floor.
Durasel posted that he had sealed that opening to prevent the water from coming back into the cabin. He's exactly right. I contacted him, got some advice, and proceeded to do the fix on my Taurus. Some folks asked for pictures, but once you put everything back together, it's a pain to get a pic. I took a couple of pics to document the fix from start to finish.
AC drain through passenger firewall - This is a picture of where the water comes in on the passenger floor. Once you remove the plastic piece under the glove box, you will have a better view of it. The water runs in through the bottom of the black foam.
AC drain side view - This is the view from the passenger side wheel well after you take the the wheel off and the wheel well liner off. This is the easiest way to reach the AC drain.
AC drain top view - this is a pic of the AC drain seen looking down the firewall on the back right side of the engine. You can see it, but you can't reach it without removing a bunch of hoses.
AC drain after silicone application - this is what my AC drain looks like now that I've put about half a tube of clear silicone sealant around the opening. I tried to seal the actual drain opening to the firewall insulation so the water woiuldn't be able to run back in.
Silicone - this is the silicone I used. Worked like a champ!
View from the right wheel well - another pic of the AC drain from the passenger wheel well.
Hope this helps.....there's been a lot of confusion in some of the previous threads about where the water was coming from. My passenger side floor has been bone dry ever since I made this fix.
