I thought I share here that my A/C - specifically the evaporator - was
leaking water into the cabin. As a result my floor carpet on the
passenger side was soaking wet and developed a mildew odor smell.
There is the small pipe that is supposed to direct the condensate
water out by going through the firewall. The pipe is horizontal. The
water itself is not truly dripping down from the end of the pipe but
rather running back on the underside of the pipe towards the firewall
and then down on the outside of the firewall. The hole that is in the
firewall is probably twice the outside diameter of the pipe and sealed
from the inside with a foam like material. I guess after 10 years the
foam got somewhat brittle so that the water made it back into the
cabin. Fixing the issue was easy: I slid a 5/8" hose over the pipe
end, secured it with a clamp and directed the hose down (actually
secured it with a cable tie to the splash guard so that it does not
constantly just drip on the lower control arm). Cost for parts: $3.
Needless to mention that I took the whole floor carpet out and laid it
in the sun for 3 days to completely dry out, especially the underside
padding material. Taking it out took a little more than one hour,
putting it back in about 2 hours.
2000 Dodge Ram 1500 V8 5.9l 2WD 135,000 miles.