my heat will not switch when i turn the knob from feet to windshield

Hello, when the air flow does not come from the desired location and is unresponsive from the controls, it’s a sign that there is likely a concern with the mode door actuator, or the plastic plenum parts that are associated with it. The motor turns doors that direct air flow to the desired locations. If the motor fails, wiring fails or the plastic of the door or plenum fails, then the door will not turn as needed and air will not come out where desired, regardless of temperature. Have this area checked. www.repairpal.com/repair-shops