So I've had this going on for a number of years and never have figured it out but I'm wanting to fix up my Ranger a little nicer. The passenger side middle of the floor gets damp, but not soaked. Like running your hand over the carpet you can't really tell it's wet but if you lift up the edge of the carpet there you can see it's wet. It also seems to be doing it on the driver's side to an extent but more so on the passenger side. There is no wet under the seat or behind the seat. It's a regular cab 2 door. I've known about the third brake light for awhile and have replaced it even twice with new Ford units but I don't think that was it. My headliner was starting to sag and saw that it was getting wet but that I discovered was the rear window seal. I've replaced the butyl seal around the slider window a couple weeks ago and that seems to have stopped that. I've still got the headliner out to test for leaks when it rains and I see nothing coming in behind the seat. The door seals still look soft and pliable, I don't suspect those. I'm wondering if it could be the windshield urethane giving out. It was replaced probably 15-16 years ago. It's hard to tell because I don't see any water trail, just a wet spot. It's definitely not a heater core. My windows don't fog up with defrost or heater use and I'm not losing any coolant at all. Is there anywhere under the hood or the cowl I need to check? I would like to have this thing totally dry inside.

 

Could be the AC evaporator condensate collector port is plugged. It should be a rubbery nozzle thing sticking into the engine bay on the passenger side. Poke a piece of wire up there or use compressed air.

Here's a good video. They're in the same general place across brands and models.

 

I peeled the carpet back on the passenger side and sprayed some water on the area of the roof and nothing happened. I then moved down the direct spray from the hose to the area around the cowl and with the hood open around the evaporator box. I finally started to see some water running down shown in the pictures. I don't know if it originates from the cowl area or the evaporator box. I drenched both areas with the hose. It's actually started to form a small amount of rust where the water collects but right now it's just surface rust. So I need try and figure out what needs to be fixed. Any ideas?