Air Conditioner Drain Problem

Sone water from the air conditioner drains on the carpet on the right side of the car. The drain hose is open and water in draining from it. Where could I look to find the problem?
It is a 2003 caravan

Have someone blow compressed air in the drain hose to clear it out. There may be water dripping from the hose, but is it draining out fast enough to prevent water from spilling into the passenger cabin?