Some 2009-2010 Lincoln Navigator vehicles may exhibit a noise coming from the dash area after the engine is started or when the customer requests a heating ventilation air conditioning (HVAC) temperature change.
Test both driver and passenger side temperature blend door actuators on dual zone HVAC systems.
1. Start the engine and set the heater control to full heat. Repeat for full cool setting. If a clicking noise is not heard at either end of the travel, do not continue with this procedure. If a clicking noise is heard at either end of the travel, proceed to Step 2.
2. Replace the temperature blend door actuator with revised parts. Refer to workshop manual section 412-01.
NOTE: The ignition key must be in the off position when replacing the actuator. Energizing the actuator before installing the HVAC case will cause the part to become mis-positioned and correct orientation will be lost.
The revised temperature blend door actuator is available as P/N AL3Z-19E616-A.