Moisture under carpet

[Jamesb155]

My 2013 Yukon Denali been having moisture under the DRIVER side carpet only when running the A/C in 90 degree weather. It’s not the heater core cause my coolant levels staying the same and I’m not smelling a sweet smell/coolant. It hasn’t been raining AT ALL! Just hot days when i run my A/C I notice moisture starts to build up… i check the A/C drain line in the front passenger fender and it seems free of debris. When I put my hand over the drain tube i can feel like air coming out of it so I don’t know if that’s a sign it’s clear of debris or not but I sticked a zip tie in it to see if it’ll drain some water that’s possibly back up but nope! It IS dripping water like normal so I’m assuming that’s fine. I’m completely lost at this point. It’s only happening on the driver side!!! The passenger side is GOOD/DRY!! Next ima take the driver seat out and pull the carpet all the way back and see what find .. I don’t know what else to doo .

 

[OR VietVet]

Welcome to the forum from Oregon.

Does sound like evaporator sweat traveling in the heater box. If you have been running a/c in 90 degree weather, there should be water dripping at that evap drain.

 

[Jamesb155]

Welcome to the forum from Oregon.

Does sound like evaporator seat traveling in the heater box. If you have been running a/c in 90 degree weather, there should be water dripping at that evap drain.

The evap drain located at the firewall on the passenger side right ? I’ve check that

 

[PG01]

But what hes saying is if you are running the a/c does it in fact drip from the passenger side?
If no condensate ids coming out from the condensate tube while the a/c is running water nay be backing up and running to the driver side.
Water follows the path of LEAST resistance…

 

[Jamesb155]

Welcome to the forum from Oregon.

Does sound like evaporator seat traveling in the heater box. If you have been running a/c in 90 degree weather, there should be water dripping at that evap drain.

Whatever the black box is under the seat is, I noticed moisture starts to build up around it or towards the side of it more towards the center console

 

[Jamesb155]

But what hes saying is if you are running the a/c does it in fact drip from the passenger side?
If no condensate ids coming out from the condensate tube while the a/c is running water nay be backing up and running to the driver side.
Water follows the path of LEAST resistance…

It does drip!

 

[Jamesb155]

Welcome to the forum from Oregon.

Does sound like evaporator seat traveling in the heater box. If you have been running a/c in 90 degree weather, there should be water dripping at that evap drain

 

[PG01]

You have a sunroof? I would check the drains in that. Shark fin gasket in good shape?
Bust out a hose snd spray the front left corner of roof above door windshield a pillar rtc …..and start searching indide.

 

[OR VietVet]

It does drip!

But you did not say that before.

 

[Jamesb155]

You have a sunroof? I would check the drains in that. Shark fin gasket in good shape?
Bust out a hose snd spray the front left corner of roof above door windshield a pillar rtc ….

You have a sunroof? I would check the drains in that. Shark fin gasket in good shape?
Bust out a hose snd spray the front left corner of roof above door windshield a pillar rtc …..and start searching indide.

It hasn’t been raining at all. So the sunroof wouldn’t be an option. It only gets damped when running the A/C it seems like. The sunroof drains are clear, I’ve been tested that cause I was getting a puddle of water on the driver side floorboard on rainy days but I’ve fixed that 2 weeks ago.. I had to reseal a seam behind the fender.

 

[Jamesb155]

Welcome to the forum from Oregon.

Does sound like evaporator sweat traveling in the heater box. If you have been running a/c in 90 degree weather, there should be water dripping at that evap drain.

Does the driver side have anything connecting to the A/C ?

 

[PG01]

Does the driver side have anything connecting to the A/C ?

No

 

[Jamesb155]

Update:!!! So I removed the front seats + center console and inspected the area, no sign of water, rust or anything that would catch my eye. So I just cleaned everything while I had everything out, and I added some dynamat on both driver and passenger side and since then I haven’t gotten any moisture under my carpet! I assume the moisture was coming from the heat on the floorboards, I’m not too sure but it’s fixed!