Heater will not turn off and A/C will not turn on

Hello,

This is common when the mode blend door actuator goes out. here is a guide to walk you through the repair with instructions on how the job is done one your car in the diagrams below:

https://www.2carpros.com/articles/replace-blend-door-motor

You may have a vacuum leak under the hood that supplies the HVAC system as well. this guide will help:

https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.