Heating and air conditioning in a Mustang

Make: 1995 Ford Mustang Mileage: 163872 Engine: V6 when using my heating or air conditioning I can only get the air to come out the defrost it doesnt matter which option it is on whether it be the floor, the vent w/e it is it only comes out the defrost. When I have it off the air still comes out the defrost a little bit but not too much I think it might be the switch but I wanted to see if you knew thank you for taking the time to read and answer this