Its most likely your heater core Heater core is on the passenger side so if it is broken, it will be wet over there. However, what it will be leaking is antifreeze which will smell, and make the windows fog up with an oily residue. If the leak is simply water you either have a bad windshield seal or possibly sunroof (if present). A leaking sunroof can cause water to run along the top of the header panel, down the windshield support and drip out under the dash. Additional Note: I just experienced this same issue - Pool of water after heavy rain on the passenger floor. Found the Gasket for your Cabin air filter was not on correctly. Allowing water that is suppose to run off from the front windshield down the drain plug to drip down into the car - through the air filter. Remove the cover to the Cabin air filter. Under the passenger side windshield wiper. Plastic screw holds it on. There is a gasket along the top edge. Make sure its on completely and sealed.
bad door seals
take it to a mechanic and get it repaired.
YES.
which O ring? there are quite a few in the 98 monte.
The fuse box on a 1995 Monte Carlo LS is on the passenger side as you open the door look on the side of the dash
This is either the heater core leaking coolant or the air conditioning drain line is plugged. If the water tastes sweet on your tongue or is warm it is from the heater core.
On the passenger side on the firewall.
on passenger side , on the side of the dash
On the passenger side, next to the door
The evaporation solenoid on a 2001 Chevrolet Monte Carlo SS is on the passenger side fender wall. The evaporator tube dispels liquid near the inside of the passenger tire.
The 2003 Monte Carlo air conditioning drain is located on the bottom of the floorboard. The drain will be on the passenger side of the vehicle.
Open your passenger door there will be a door on the side of the dash