heat/ac only blows out of the vents on my 2011 crown vic police interceptor.

Hello, The vents selection is adjusted by mode door actuators. They are attached to the exterior of the HVAC housing (big black box behind the dash), and control little doors inside the housing. When these doors are turned, it changes the flow of air to the location you requested. The failure could be a result of a bad fuse, or the actuators/doors could have failed. Check the fuses first, and just know that if the blend doors have become damaged, the dashboard has to be removed to repair the HVAC unit. However, if the actuators are ba, depending on location, they may be accessible without going to this extreme.