Water leak from ??, into driver side floor

I have found water collecting under the mat on the driver side floor of my 96 roadmaster wagon. It's not a one time thing. Any thoughts on what or where to begin sealing?

Thanks,

Tom

Common problems are the AC drip pan under the dash or the 90* drain hose on the outside of the firewall. You will either see the drain hose, located just below where the heater hoses connect at the outside of the firewall. Or, you will see a bare pipe sticking out of the firewall, @ 5/8 inch in diameter.

This is the problem I had about 10 years ago.

https://www.impalassforum.com/vBulletin/7-concerns/236840-rain-water-leak-inside-front-firewall-recent-winshield.html


Tom