I don't know what else to do. I still get rainwater on the passenger side floor of my 2002 extended cab 4wd v6. I have checked for bloackage in the AC overflow drain, seam sealed the pinch weld on the firewall as per the TSB, even took the fender off and seam sealed that weld. Can anyone think of anything else to do? It's driving me nuts, and I have a brand new vinyl mat to install, but I don't want to until I'm sure the leak is sealed.
Thanks for reading, hopefully someone has input!

 

Try pulling the door panel and looking at the service hole cover. It is a plastic weatherproofing layer attached with butyl tape to the door frame. Sometimes this cover gets tampered with and not replaced or repaired properly allowing water to drip from the inside of the door. I had this problem on my 4Runner.

 

Check your antenna seal. The cable from the antenna runs to the head unit above the passenger floor.

 

It sounds like you're unaware of the leak source.

Sit inside the truck with a good flashlight, while a helper drowns sections with a hose. You should see it seep in. (Don't blast it, soak it. Let gravity, not pressure, do the work)

It could be from the antenna, could be from the cowl filling up and not draining outside, could be from the door seals, could be the door 'shower curtain' liner, could be the window seals... Could be a floor plug missing... Could even be windshield seal.

If desperate, break out a bottle of baby powder. Dust everything inside, then take a garden hose to the outside of the truck. Aim at one section at a time, then check the powder for new leaks.

 

Sunroof?

 

look on the firewall. there is a round rubber grommet / seal that will leak. i had the same problem