It sounds like condensation buildup from the air conditioner. There's a little pan under there somewhere that collects it (not sure where). You might also notice a moldy smell. Try running just the blower fan on high, no AC, for ten minutes or so.
replace heater core. replace fan.
Underneath the dash on the passenger side.
should be somewhere underneath the passenger side dash glovebox area
in fuse box,or underneath dash board on passenger side.
That is where the heater core and AC box is located. Perhaps the drain is plugged and water in getting into the air intake under the hood somehow. The drain is in the firewall at the bottom or underneath. After the AC has been running, there should be condensation dripping from it if it is open.
underneath passenger side of dash! below glove box!
The blower motor is underneath the passenger side dash.
The drain for the condenser may be clogged.
Underneath the tray ontop of the passenger side dash.
If equipped, it is located under the dash on the passenger side. There is a access door from underneath.
The ECU is located inside the footwell of the passenger side of the cabin. To find it remove the carpet from underneath the passenger side dash.
it should be located on the passenger side floorboard (inside) just up underneath the passenger side dash