Water Leak Passenger Side Floor

First make sure it's not coolant from the heater core :)

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The first signs of a leaky heater core are a defroster that doesn't work anymore (it just fogs up the windshield) and a sweet smell inside the passenger compartment. A puddle on the floor is a really advanced sign.

Earle

Very true, however they do sometimes just let go. Happened to me a few years ago right smack in the middle of winter. One morning I heard an bubbling/burbling noise when I warmed the car up and that evening there was a puddle on the floor.

COULD BE RADIATOR LEAK, BUT ALSO WHEN THE AC DRAIN PLUGS UP, SOMETIMES THE CONDENSED MOISTURE (WHICH CAN BE LOTS WHEN IT IS HUMID AND THE AC IS WORKING OVERTIME)FROM THE AC SEEPS BEHIND THE AC/HEATER HOUSING DOWN UNDER THE CARPET FOR A LONG, LONG, TIME AND EVENTUALLY SOAKS THE CARPET WHEREIN YOU FINALLY NOTICE IT. IF YOU PULL THE CARPET UP YOU MAY FIND LOTS OF WATER EVEN SOMETIMES TO THE POINT THAT THE FLOOR BOARD UNDER THE CARPET IS STARTING TO RUST/ROT. THANKS, DAN

I don't know about the Jeep core, but the GM heaters had plastic end caps and when one of those suckers let go on me it wasn't a puddle, it was a POOL. Cold day, middle of traffic, 3 inches of HOT water on the floor and widows fogged so bad that I had to stick my head out the window just to get off the road. At least the all metal cores have the decency to give a little warning.

No, its not the heater core, its plain ordinary rain water.

Snow..

Mine leaks from the door seal, but only under very heavy rain.