Both floors are wet and I have not driven the truck in over a week. I do not smell anti-freeze so hopefully it’s not the heater core. The tube next the evaporator is in place at the firewall so that is out. The truck has not been parked on level ground so I can’t be sure if it started at the back or front of the cab. I’ve only had it a few months so I don’t know the history. Where should I begin? I am taking any and all suggests. Thanks.