Hate to be the one to give you the bad news but the problem is with the blend air door in the heater and a/c box. Normally what happens is this door breaks and needs to be replaced. There is a chance it is just the actuator, but either way the dash has to come out to find out.
If you have the dash out then you should be able to finish the job. I will attach information on the housing and the door.
If you still need help just reply, if not click ACCEPT when we are done.
The HVAC housing must be removed from the vehicle and disassembled for service of the A/C evaporator, evaporator temperature sensor, mode-air and blend-air doors.
INSTALLATION NOTE: The HVAC housing must be removed from the vehicle and disassembled for service of the A/C evaporator, evaporator temperature sensor, mode-air and blend-air doors.
REMOVAL WARNING: Disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to take the proper precautions could result in accidental airbag deployment and possible serious or fatal injury.
If the battery is disconnected that is all that needs to be done for the air bag system.
The a/c will need to be evacuated before you can get the housing out. Then will need to be recharged after the repair.