Hey! Thank you for the reply! Funny thing is a while back while I was at one of my construction job sites one of my subcontractors actually helped me out by sealing that exact same spot! I'll check it today, I never took a super close look to make sure the sealant is covering all of the spot that my windshield sealant was gone. Used an air compressor and some soap to check my windshield and it has no leaks (honestly thank goodness cause that would not have been cheap). It seems to be coming in somewhere under the cowl, but taking off my wiper arms has been a pain in the butt. They are totally stuck on, trying to now figure out how to get them off. But thank you for suggesting the spot, and I am going to take your advice on that odor eliminator!

 

ah yes I forgot about the cowl. If the drains are plugged then water can start to overflow and go inside. Same thing with the A/C evaporator drain.

Good work with the compressor. Another trick is to turn the fans on full, and listen/watch for air from the outside.

 

I experienced a situation where I was getting moisture build up under the rubber mat and carpet on the driver side of my 03 Silverado. It was driving me mad trying to figure out where this was coming from, trying to trace seals, leaks or anything that may lead me to the root cause. I couldn't find anything. It had no odor like anti freeze so it wasn't a heater hose leaking so I narrowed it down to plain water of some sort, but where from and how is it getting in?? My carpet and mat would be wet on non rainy days so that really threw me for a curve. I finally narrowed it down to the AC Condenser. The condenser has a plastic sealed housing around it that also serves as a catch-pan for condensation build up. Attached to the bottom of that pan is a rubber tube that leads out to the firewall of the truck to drain. Turns out, I had so much crud or sludge built up (decades worth) in that catch pan that the drain tube got clogged leading to overflow and ultimately leaking water from the top of the catch pan that clipped to the condenser housing. I popped the hood, and took a can of compressed air and gave the drain tube a few good blasts then an incredible amount of water poured out. Since then I've been high and dry!...well just dry anyway

Now this may not be the same problem, but maybe worth looking into. I know even on cold days when running the defroster setting on the windshield, I know it engages the AC compressor so its running and if the humidity is moderate to high in your area, you will get condensation build up inside the condenser housing. And if its clogged, the overflow is what's making the floor board wet.

 

Thanks for the report Nicholas. This seems to be a common problem. So when the catch pan overflows, where does the water come out of ... the heater core housing?

By the way, the condenser is located in front of the radiator. The part you are describing which cools incoming cabin air is called the evaporator.

 

Sorry for not replying quickly! I'll check this out, at this point I'll try anything!

 

It's not from the windshield, it's coming from the cab vents in between the cab and bed... had to hang dry my entire carpet and padding out for 3 days in the sun to dry.