Spent the day checking out the whole passenger side door for the leak but couldn't find anything. The whole front floor and area between seat and door was wet. Didn't notice it wet anywhere else but didn't check everywhere. Anyone have any ideas of where the water is coming from? It is definitely not coolant and the truck wasn't driven, so it wasn't AC leaking from the drain tube or splash up from under the truck. This is driving me crazy. Please help!

 

Had the same problem with my truck for a good year. After heavy rains the passenger side would be soaked. Read here about checking the third brake light and so took it off and added another small layer of seal tape and not a problem since.. You change one of the bulbs in the light recently?

 

No I haven't but I only recently purchased the truck. Seems kind of strange that the front floor would get wet from the light in the rear but stranger things have happened. That is one thing to check. Thanks.

 

I lifted up the floor mat on my passenger side in my truck a while back and there was a puddle..i was told it was my heater core..dunno if that i whats going on or not but mine still leaks too

 

The heater core is the one thing I know that it is not. The water is clear and has no sweet odor, actually has no smell at all.

 

Might be condensate from the A/C (water), Or, it might be rainwater leaking in from somewhere. The third brakelight is a favorite spot.

 

It is definitely rainwater. The truck hadn't been driven all that weekend. I have to check the brake light. Is there any other common problem areas? It's not the door, thoroughly checked that.

 

Sorry. I dont know much about the heater core so I didnt know if it was a possibility.

 

I had the same problem mine was the rear window. I also sealed the thrid break light with duck seal

 

I had the same exact problem on my 1999 1500 5.2L 2WD Club Cab. I pulled the carpet back and could see the rainwater dripping down the inside firewall on the passenger side. I kept a towel on the passenger side while looking for the problem for 2 years. I noticed the problem in 2007 and could never find it. I did not have the leaking problem last rainy season. It was definitley not the brake light gasket on the top of the cab as I addressed that early on and that did not fix it. And it definitley is rainwater. I don't know if there was / is something like leaves clogging a drain in the bottom of the windsheild allowing rainwater to come down the passenger side firewall. I hope you find the reason yours is leaking as the problem is annoying. You need to keep the carpet off the floor to keep it from mildewing.