Garrett Fulton
Newbie
The clicking is coming from the recirculation door actuator. In my opinion, impossible to replace without pulling the dash out. The other two actuators have position feedback to the HVAC controller and run to their commanded position and stop. The recirc. door actuator runs either full open or full closed and there's a 10 second time delay that holds power to the motor. The plastic teeth get old and brittle and one pops off and the gears drive against the gap and make that popping sound for about 10 seconds when you shut off the engine that drives people nuts.