Possible Causes
WARNING: This page is about a different car, the 2002 Lincoln Blackwood. However, it is still accessible from the selected car via links, so may be relevant.
- Low engine coolant level.
- Engine overheating.
- Plugged or partially plugged heater core.
- Temperature blend door binding or stuck.
- A/C electric blend door actuator.
- Incorrect heater control valve operation.