Component Tests and General Diagnostics

If the heater outlet air temperature cannot be adjusted with the temperature control knob on the heater-A/C control panel, the following could require service:
- A faulty heater-A/C control.
- The temperature control cable is not connected, or is not routed or adjusted properly.
- A faulty, obstructed or improperly installed blend-air door.
- An obstructed cowl air intake.
- The engine cooling system.