A few days ago I was cleaning out my car and noticed that the front passenger floorboard was damp. Also, when it rains, the windows fog up from the inside. Are these problems related? What could be the cause(s)?
Have the A/C system checked to see if the drain is clear for the A/C evaporator case. If you park under or around trees that shed a lot then it can get debris into the A/C and clog the drain, causing it to overflow into the passenger side floor in some cases. When it rains outside and heat and humidity builds up inside the car, the water on the floor will fog up the windows. If the A/C drain is not plugged and the A/C drains properly then you may have a water leak somewhere. The leak could be on the passenger side cowl or windows, or the windshield. A certified mobile mechanic from YourMechanic can come to your home or office to inspect where the moisture is coming from.