I hasd a similar problem with a 1990 Camaro. My carpet was wet from a leaking heater core. Smell the carpet where it is wet. Does it smell like antifreeze or is it the color of antifreeze? If so nyou have a bad or leaking heater core. Good Luck
Floor at passenger side? Could be heater core needs replacing Other possibilities: door seal windshield seal
Typically the front passenger side floor/carpet gets soaked with engine coolant and when you turn on the defroster, the inside of the windshield fogs up.
your heater core is leaking
You probably have a bad heater core. Find where it is coming from. You probably have debris stopping up the drain below the windshield.
Anti-freeze smell inside vehicle when you turn on the heat. Greasy windshield from the anti-freeze leaking from the heater core while the heat is running. Also check the passenger side of the vehicle carpet under the carpet and check the heater core hoses under the hood of your vehicle for anti-freeze leaking at the fire wall where the heater core hoses go. That about covers it. If all checks out do a pressure test on your anti-freeze circuit and this will definitely bust the culprit of the leak. Last of all, if you have no leak and your heat is not working and the heater core is in circuit with the anti-freeze with no leaks, replace the heater core. C.S
You either have a leaking heater core, leak at the windshield, or a A/C condenser drain line stopped up. Taste of the water. If it taste sweet, it is coolant and your heater core needs replacing. If not then, check the drain line. Look under the car, passenger side, and find the line. Use a pencil or other blunt object to clear it out. If the line is clear, you have a windshield leak. Take it to an auto glass shop and have it fixed by a pro.
Usually that is a sign that the heater core or windshield are leaking.
you will have coolant in your passenger front floorboard and when you turn your heater on your windshield will fog up
Fluid on the passenger side floor is one of two things. Either you have a water leak from outside, as in a windshield leaking, condenser drain line stopped up and leaking into the car, or the heater core is leaking. Taste the fluid. If it taste sweet, it is coolant and the heater core needs replacing.
have your heater core checked its probually leaking
your heater core is bad you may also experience steam in the windshield
Passenger side firewall