The carpet on the floor of the front passenger is wet
 

1995 Mazda Protege LX 1.5L.

I just noticed that the floor on the passenger side in the front is wet. It seems to be only located on the floor board and not under the dashboard. It doesn't smell so I doubt it's coolant.

Can anyone please tell me what this could be?

Does it look or smell like coolant? Otherwise rain is getting in somewhere.

I was thinking it was the heater core as my heat never works but there's no smell to it.

There is a drain tube for water to exit the air plenum. A/C dehumidifies the air and the water has to have a way out. Yes it's cooler out now, the A/C runs on defrost mode to dehumidify and clear the windows. The tube should be visible on the outside of the firewall towards the passenger side of the vehicle, or may be only seen from underneath. Either way, check there first

Thank you but I have no clue where this tube is located. All I see when I look under the dashboard is a BIG black part that's plastic and I believe the heater core is inside. Other than that the only tube I saw went to the blower motor and that shouldn't have come loose.

Drain tube located on the outside of the vehicle. Wouldn't make sense to drain inside the car.

Look I never said it was outside of the car. I have no clue where this is.

Sorry, the drain tube for the A/C is located on the outside of the vehicle. If and when it clogs, the water remains in the duct work and eventually spills out onto the floor, passenger side.