I've been chasing this wet floorboard issue for I don't know how long now. It smells like a swamp inside my truck! I'm pretty sure it's due to the AC leaking because I don't see a water puddle under my truck when the AC is on. I attached a piece of heater hose on the evaporator drain a long time back and shoved a wire coat hanger into the drain tube but its dry as a bone in there. I have also recently replaced the third brake light gasket because that was leaking. What else could it be?

Thanks in advance.

 

There is a seal between the condensation drain on the HVAC housing and in the inside of the firewall. Perhaps liquid is getting in there. It was on mine. The underside of my passenger side carpet was wet. I used black silicone adhesive to seal around the drain tube and the engine compartment side of the firewall.

 

if the drain seems clear, try drilling a small hole in the heater box near drain (careful not to drill too deep, hitting evap or heater core) and see if it drains water or not,hole can be fixed with RTV later

drain could be plugged up further than the coat hanger reaches, or try pulling hose off and cleaning drain again

 

it's either the ac, which is most likely or the third brake light. Removing the light and cleaning and replacing with clear silicone will eliminate that. Putting a hose over the end of the ac drain stub and zipping it to the frame rail will stop the ac issue.

In the meantime, you need to take the seats out and remove that carpet and pad. The water will NEVER dry out under there. I vac'ed at least 5 gallons out of mine when my ac drain leaked. Hang the carpet and pad up high so the water will run out of it and the sun and wind will work in your favor.

You can put the seats back in with no carpet and pad and drive it a few days as it has time to dry. I did this with my 99 and mine was all fine and dandy.

And a note to everyone else who reads this regardless of year model. If your ac isn't draining into the cab yet, it will. You can prevent this problem by adding a 3/4" hose to the drain. Simply push it over the short drain tube, then zip tie it somewhere on the frame rail.

 

Mine did that about 5 years ago and it was the 3rd brake light. Pulled the seat raised the carpet put a fan on it for about 3 days Got a seal from dealer and stopped it. Probably about time to do it again. Mine was just wet on the lower passenger side.

 

The other day after I got home from school I layed under my truck with it running and the ac on full blast and it started dripping out of the heater hose that has been installed on the drain so water shouldnt be getting into the cab from there. Maybe I have a rear window seal going out or water leaking through my cab lights? Dodge doesnt sell replacement gaskets for the cab lights so I may have to make my own. I'll break down one day and pull the carpet but i dont have time right now due to school. I appreciate everyone for the replies!

 

Another way to check for leaks is tape off the vents on the rear of the cab , turn blower on high and wash your truck , bubbles will form where air is escaping.

 

It is your 3rd brake light on the roof leaking, very common problem and it runs down the side of the cab emptying on to the passenger floor.

 

Just seal the light with clear silicone.

 

I found the problem. I took out the blower motor and stuck my hand in where the evaporator is and found a bunch of crud and dirt in there. Some water is getting backed up in the a/c box and dripping back into the cab. I took a garden hose and fanagled it up in there and sprayed a bunch of that crud out but I still feel that it's pretty dirty in there. Is there any other way to clean out the evaporator without pulling the dash and the a/c box?

 

The only way, other than what you've been doing, is to remove the dash and the HVAC housing. In order to remove the housing though, you will have to disconnect the A/C lines. You'd have to remove the heater core hoses too, but that's no big deal.

Be careful when running water through the blower hole and over into the evaporator section. You can run too much water and end up running out of the left side of the evaporator, just above the transmission hump. I guess that's probably where it's already been leaking into the cab though.

 

Yea I found out about the water running out the left side of the evaporator but no biggy I had the carpet pulled out and the floorboards coated with rubberized sound deadener last week. Hopefully I'll have no more leaks since I siliconed both sides of the drain tube and cleaned everything out. Now when I turn the a/c on the blower motor doesn't sound like a 747 taking off, doesn't stink like a marshland, and pees water outside of the cab and not in it!