Check to see if your coolant is low. If it is, you could have a heater core with a slow leak. Antifreeze will have a sort of sweet smell to it.
If your coolant level looks fine, check to see if the water drain from the heater case is blocked. If it's blocked, your AC evaporator will "sweat" (they all do it) and that sweat has nowhere to go...eventually it will drip out onto the passenger side carpet. This would be fairly probable if you have trees near where you park the vehicle, as leaves/needles from the trees can get in there an plug up the drains! The drain hose will be visible from under the vehicle, in the engine compartment, off of the firewall.
Last edited by reddjeep88; 09-28-2009 at 06:28 PM.