That is either a bad mode door actuator or bad HVAC control head.
The actuator is a common failure, it is easy to replace. Basically you remove the isolator panel above your feet on the drivers side (it's the panel that hides the stuff behind and under the dash on the left in the picture) it is held on with a simple push fastener.
Now look up and to your right and you will see the mode door actuator (other picture)and its wiring. Disconnect the wire connector (it will probably have a red lock tab that has to be pulled out so it will release) then remove the screws, install the new one in reverse of the removal process.
Images (Click to enlarge)
Wednesday, July 12th, 2017 AT 3:17 PM