RAM 1500 Truck 4WD V8-5.7L VIN D (2005)
Air Door Actuator / Motor: Description and Operation
Actuator-Blend Door
The blend door actuators are reversible, 12-volt direct current (DC), servo motors. Models with the single zone heating-A/C system have a single
blend-air door, which is controlled by a single blend door actuator. Models with the dual zone system have two blend-air doors, which are controlled by
two blend door actuators.
The blend door actuator (1) for the single zone heating-A/C system is located near the center of the HVAC housing (2), close to the dash panel.
For the dual zone heating-A/C system, the same blend door actuator used for the single zone system becomes the driver side blend door actuator, which
is mechanically connected to only the driver side blend-air door. A second separate blend door actuator (3) located on the top of the HVAC housing is
mechanically connected to the passenger side blend-air door.
All actuators (1) are interchangeable with each other. Each actuator is contained within an identical black molded plastic housing with an integral wire
connector receptacle (2). Each actuator also has an identical output shaft with splines (3) that connect it to its respective door linkage and three integral
mounting tabs (4) that allow the actuator to be secured to the HVAC housing. The blend door actuators do not require mechanical indexing to the
blend-air doors, as they are electronically calibrated by the A/C-heater control.
The blend door actuators are connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the
HVAC wire harness. The blend door actuator(s) can move the blend-air door(s) in two directions. When the A/C-heater control pulls the voltage on one
side of the motor connection high and the other connection low, the blend-air door will move in one direction. When the A/C-heater control reverses the
