FWIW, I have the 03 Expy with continuous rear air unit "clicking" or more accurately flapping of the air damper while the plastic gears in the 2L2H-19E616-AA grind away into toothlessness. Ford designed this unit to find the end of travel by jamming the motor to a stop and monitoring the current to determine when to stop applying voltage. That would probably be fine if the gears were designed to handle the jammed torque or the motor did not slip out of groove and continue turning and cracking the plastic gears. How can Ford continue to provide its customers the pleasure of paying for this obvious design defect? I guess those without conscience get away with what you can when they can.
The rest of the rub is that the two gears that get chewed up cost WAY less then $1. I think that most of you know how much it costs to replace those $1 parts. THANKS FORD!
