(Fixed with regular old packaging tape)
First off, the leak is due to water getting inside the air conditioner's air intake. Water runs down the passenger side windshield and flows between the windshield and the crowl (the crowl is the big flat plastic seal connected to the bottom of the windshield). Therefore, Ford put in a gutter on the bottom-side of the crowl that is supposed to collect this water and move it elsewhere to a safe place.
The leak occurs because this gutter doesn't have a big enough lip on it to keep water from flowing over the gutter (similar to how a bent-down rooftop gutter would overflow when it rains). This water flows into the air conditioner's air intake, which is located directly beneath the crowl. Ford should have fixed this problem! They've had six generations or more cars with this same problem.
Instead of fixing this gutter (by adding a bigger lip on it), I decided to start with the easier route of covering half of the air intake with packaging tape. To do this, you need to lift up the hood of the car and lift up the crowl. There are 3 clips on the crowl that need to be unclipped and you can lift up the crowl afterwards (with a bit of wiggling) at least enough where you can get your arm underneath it.
Once you have the crowl up enough, you will see the air intake covered by a grating. I simply cleaned this surface and placed packaging tape over half of the grating (the half that is towards the center of the car). You need to make sure that the tape covers the grating and the grating's housing so that there are no gaps such that water can still flow into the air intake. I actually took out the entire housing so that it would be easier to clean and get to, but this is a little bit difficult and requires a wrench.
Also, I took a cheap plastic mechanical pencil (or some rod) and taped that down the center of the grating so that this would provide a lip so that water cannot get from the taped half of the grating to the untaped half of the grating. This might not be necessary, but easy enough to do.
We had heavy rains and I lifted up the crowl to see if my rigged-up fix actually worked and it worked much better than expected.Answer
Most vehicle that have this problem, and being a ford man, it's your heater core! What's a heater core? In laymen terms, is't a miniture radiator that water come's from your main radiator cycles through the engine and in to your heater core and back through the radiator. You know when it's winter and it's cold and you turn on the heat inside the car, well that's how you get heat from the heater core. Either it's a loose hose connection ( doubt it) or you need to replace the heater core and that's not fun. That's where your problem is and you need to replace it now or flood the floor board of your car.
During the summer, it is NOT the heater core unless your car is a sauna. If it is only on the passenger side, I'll also bet it only happens when the air conditioner runs. Look under the car around the firewall on the passenger side for a small tube hanging down. This will be the drain for condensation on the AC. Carefully poke a wire up this hose to clear the blockage.Answer
All good information but I had the identical problem, and it could be this. One morning after it had rained I had a puddle of water on the front passenger floor. I traced the water entry up to the openings where the heat would come out. First I thought it was the heater core or something but the water was clear, and it had rained. Then I thought it was the windshield as I had heard about some windshield seal problems. So the next Saturday I took the trim piece off which is just below the wiper on the passenger side to give it a look. When that was off I could see a cowl that is the air inlet for the heat and a/c and could look down and see the fan. So I next took a few cups of water and poured it around the cowl where the rainwater would normally flow and lo and behold, it started to drip into the fan area. The cowl was not sealed properly to the metal shroud that it was attached too. It was pretty easy to remove the two nuts and because the rubber gasket was still in good shape, I kept that and put a small bead of silicone on the gasket, cleaned the mating surface and put it back together. Problem solved for free in a couple of hours.
Passenger's side? Could be a leaking heater core
heater core is leaking.
If that water is engine coolant, the heater core is leaking.
bad door seals
This would be caused by a leaking heater core, or a leak in the plumbing associated with it.
water in passenger floorboard, where is the hose that would cause this?
Have you used your air conditioning lately? The most common reason for water to appear to be leaking on the passenger floorboard is that the condensation drain for the air conditioning is plugged. Unfortunately, the drain is pretty much inaccessible to the average person and I have yet to discover a reasonable method of clearing it other than paying the dealer or a mechanic to do it. The other, less common causes for that type of leak is that the heater core is leaking, in which case the fluid will be antifreeze rather than water, or the door seal on the passenger door may be leaking, or the windshield gasket may be leaking.
The condensor drain tube is clogged. Find the drain line and unclogg it.
your ac might be clogged or your draining hose is clogged. its in that area
A damaged heater core will cause coolant or water to leak onto the passenger floorboard.
because your ovberflow or condenture tube is clogged remove it and just blow it out with air
Would that be when it is raining ? If so you need to caulk around the vent in the fire wall area. If not from rain, then the heater core is leaking, and you will be losing coolant.
The most likely culprit is the heater core.. its usually located under the dash on the passenger side.. if it starts leaking you will have water on the passenger side floorboard.. also the radiator fluid will be low.. Another possibility is the drain from the ac is clogged... alowing condenced water from the ac process to dump in the passenger side floorboard.. the heater core and the ac drain are located in the same area...
My experience with Ford Focus, VW Golf, VW Polo the issue is simple :-) blocked waiste pipe which're actually hidden the result will cause fill up your water collector at the base of the windscreen and water will infiltrate through your pollen filter straight to the front passenger area. You can actually see the water dripping under your glove compartment if it's raining heavily...
Check AC drain and clear the blockage. Also look for firewall sealer skips.
the heater core is leaking it is located in the duct work under the dash
normally you have no heat and,or water on the passenger floorboard
It wasn't an impala, but I had a car that leaked and would fill the floorboard on the passenger side. It was due to a drain that was plugged with dirt, leaves, etc. that ran down from the windshield and would normally drain out under the car.
I BELIEVE THE WATER COULD BE COMING FROM YOUR AIR CONDITIONING .
Heater core leaking? Windshield seal leaking? Door seal leaking? Evaporator drain plugged?
You could have a seal leaking around a door or if you have a sunroof the drain holes might be plugged. Most cases of water leaking into the floorboard would be a plugged ac drain in the evaporater case. If you notice on a hot summer day and your ac is on that if you leave it parked, you will see water on the ground. This is from water draining out of the case, but if the drain becomes plugged it will build up in the case and slosh around and sometimes come into the floorboard.
have your heater core checked its probually leaking
plugged evaporator drain tube or the heater core has gone bad
you could have a heater core leaking or your windshield is leaking and the water is running down behind the dash and onto the floor.
There is a drain on the outside firewall that is clogged.