Operation CHARM: Car repair manuals for everyone.

Temperature Control

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:
- The heater-A/C control.
- The temperature control assembly in the control head.
- The electric blend-air door motor.
- Any associated wiring harness or connectors.
- The blend-air door.
- Improper engine coolant temperature.