The driver-side front floor of my truck has been getting saturated with water whenever there is a hard rain. I pulled all of the trim out of the interior today, to try and trace the leak. Nothing on the A-pillars, nothing inside the doors.

The carpet is soaked through, it's smelling musty inside, and I'm starting to worry about this leading to a rust problem.

A search (yes, I did) led to mention of the 3rd brake light gasket, which I ordered tonight just to be sure, but I would think the rear of the interior would be getting wet too, it that were the culprit. But it's dry behind the seat, the rear carpet is dry, and it's dry behind the trim in the rear.

All windows are closed fully, and I haven't been able to replicate the problem with a hose. It only occurs (noticeably) when there is a heavy rain.

Anyone had this problem before? Any suggestions or insight is greatly appreciated! Thanks for reading!

 

Do you have the roof marker lights? Is the door gasket damaged? If it does it in a heavy rain, you should be able to get it to leak with a hose. Try running the hose around the windshield gasket and the cowl area.

 

We've got a 99 mountaineer (191 k) that does the exact same freaking thing on the driver's carpet and i can't replicate it with a hose either. Most frustrating thing in the world, the worst time is during the winter whenever snow collects on the roof and then slowly melts... I've got a suspicion that it is the windshield, since it's as old as the car is, but we've almost given up looking because the car is so old. Best of luck to you, I'll be following this thread to see if you come up with any answers

 

I have this problem on the passenger side of my '98.
The leak seems to coincide with heavy rain.
I can't reproduce the issue with a hose.
I've gone over all roof seams, around the rear window, and 3rd brake light with flowing silicone.
Today I bypassed the heater core, just to eliminate that potential cause.
Water seems to puddle in the back corner of the cab and run forward under the sill cap, and onto the floor pan.
At one point, I noted a damp seatbelt, but thought this was due to it being out the door.
The door seals are all intact and do not seem damaged.

I'm still at a loss as to where the water's getting in.

 

I have the same issue, except on the passenger side, could not replicate the leak with a hose.
Interesting about the third brake light gasket. I checked and discovered There wasn't one in place. I highly doubt that's where the water's coming from, but it might make sense, since the front cab is slightly lower than the rear, it could be running down and collecting?

 

My sister had the same issue with her 98 Ranger before it was wrecked. Only difference is that she happened to notice it dripping out of the top corner of the windshield on the driver's side.

 

The 3rd brake light gasket seems to be a common problem with 3rd Gen trucks. It's possible, but I think I would have found at least some evidence of water in the rear.

No roof marker lights on this truck.

I was thinking the windshield too, but again, no evidence of water up there, or anywhere except on the floor.

I'm going to replace the brake light gasket and continue to search for the source. I'll report back.

 

Mine also leaks in the passenger side, mine leaks through the track on the slider window and runs down the channel where the carpet folds under and puddles in the floor pan.

 

Is the leak across the bottom, or between the pains?

 

somewhat related, but I once had an after-market guage cluster in a different vehicle. A gauge wire was shorting up against the lower portion of the cowl-vent area, burned a small hole through the metal. When driven in the rain, the water combined with the air flow there would allow for water to creep up into the hole and drip on my foot.
Found the hole by accident one day, JB Weld + a dime fixed it. Still there 20 years later.