Sounds like either the blend door stuck or the actuator for it failed.
Remove the insulator panel above the drivers foot well. You will be able to see the blend actuator on the side of the HVAC case. Try adjusting the temp from hot-cold-hot and see if the stem moves. It probably isn't moving which means the actuator or the temp control is bad. The actuator comes off easily, Try moving the control stem by hand. Do you get hot/cold now? If yes the core and door are OK.
The actuator is the likely problem.
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Monday, October 9th, 2017 AT 6:03 AM