It sounds like you have temperature mode blend door actuator that is out.
Here is a guide and some diagrams (below) that will help you get the job done:
Here is what it will be like on your car. Check the operation of the actuator by moving the pivot back and forth with the actuator removed to make sure you have the right one.
Please let us know what happens and upload pictures of the problem.
Images (Click to enlarge)
Thursday, September 7th, 2017 AT 11:17 AM