Air Door Actuator / Motor: Description and Operation

System Description - Intake Door Motor:

The intake door motor is installed on the intake unit. Using a link, it opens and closes the intake door.
When REC switch is ON, the ground line of the motor is switched from terminal (2) to (4). This starts the motor because the position switch contacts built into it make current flow. When REC switch is OFF, the ground line is switched from terminal (4) to (2). The contacts turn along with the motor. When they reach the non-current flow position, the motor will stop.