Where is the ac condensate drain tube on a 97 Dodge Ram 2500 V-10

I can't speak for your specific vehicle, but the tube is generally located directly below the evaporator box, which is towards the passenger side of the instrument panel assembly, between the panel and the firewall. Some investigation below the vehicle can find the opening, and tracing upwards can find the tube behind the dash. If it is pinched or misrouted, this could allow condensation water to go in an inappropriate place as you are experiencing. Good luck.