Leaking on passenger side of floor board of f 150 22001

antifreeze anywhere inside the cabin is a sign of a leaking heater core. Rub the liquid between two fingers. If it feels oily, it's coolant.

either the air conditioner condensation drain is clogged orb the heater core is leaking .

Sounds like the outside drain is stopped up.
There should be a tube coming out of the firewall near the passenger floor.

Usually a sign of a plugged drain tube.
The HVAC box has a tube that drains the water onto the ground.
The tube should be at the bottom of the firewall near the passenger floor.

Hello,
If you can smell a little bit of a sweet smell from the water on the passenger side floor, or if it has an oily film to it, you may have a leaking heater core.

They usually leak on the passenger side floor, and that might explain why you hear water sloshing around.

If you can run the engine for about 5 minutes and then turn your heater on. Look under the dash in the area where the dash meets the floor board and see if you can see anything leaking.

I hope this helps you.

this leak must come from the heater metric.your car has a small radiator for heating.It's in the passenger side dash board.so you have to remove the dash board and check and repair the heater system.

There is a drain to the hvac box under the hood passenger side. It's most likely stopped up.

Do you have any coolant on the passenger side floor board? Coolant causing the radiator to fog up is a symptom of a leaking heater core.

heater core and or backed up evaporator drain tube.

where your battery sits look inside there maybe some twigs and leaves blooking the drainage holes look all along there i had similar problem on vw passat no arm in looking hope this helps?good luck