Mark VII V8-302 5.0L VIN F FI (1987)
Air Door Actuator / Motor: Description and Operation
Each system has four electric motor driven actuators mounted in various areas on the system evaporator assembly or plenum. The actuator output arms
operate in a circular motion and are connected by linkage to doors within the plenum and ducts. These doors set up the air flow pattern and help establish
the system functional operation. Overall system characteristics for optimum performance are programmed into the control head to be consistent with
operator input and ambient conditions, allowing the control head to control the system door positions through the actuators. Each actuator contains drive
and feedback circuitry. The control head senses the door position through the actuator feedback circuitry and controls the door by powering each
actuator until the programmed position is reached. The control head automatically changes door position during operation as operator input or ambient
conditions change consistent with programmed performance requirements.
Each system of four actuators is comprised of two each of two types that are designated as continuous position and two position actuators.
Continuous Position Actuators
The continuous position actuators operate the blend door and floor/panel mode door. These actuators are not interchangeable since the stop points and
mounting holes are different. They operate in both clockwise and counterclockwise directions and will stop at any position within their 180 degree
operating range as directed by signals from the control head.
Two Position Actuators
The two position actuators operate the panel defrost door and the outside air/recirc door. These actuators operate only in a counterclockwise direction
and stop in one of two pre-established positions, 180 degrees apart, as signalled by the control head. These two actuators are not interchangeable. The
output arms of the two position actuators are color coded for easy identification. Care should be taken to ensure that each two position actuator is
installed only in its correct location to ensure proper system performance.
