Most likely the A/C condensation drain hose has a leak/crack or become dislodged from its outlet. It should drain through the floor of the vehicle. Check above the spot your car would normally leave a puddle outside when the a/c is running, it's possible the hose is not draining properly....
you could have a heater core leaking or your windshield is leaking and the water is running down behind the dash and onto the floor.
The heater is leaking coolant.
The Heater core on your 1997 Jimmy is on the passenger side inside the cab, but it is behind the black plastic close the floor, and very difficult to get at.
this could be from the heater core. When the heater core goes out it leaks....right into the passenger side floor board If it is water, not coolant, the problem could be a plugged air conditioner drain. Easily accesible from under the hood.
better check your heater core.
Crack in the heater core
If a Dodge Ram Van is not getting any heat, the first sign of it being the fault of the heater core would be a very wet passenger side floor board. The heater core is located near the foot well on the passenger side.
yes
Heater core is leaking
heater core may be leaking or hole in floor
Classic symptoms of a bad heater core. You need to replace it.
Leaking heater core.