Bonneville V6-3800 3.8L (1991)
Air Door Actuator / Motor: Description and Operation
Automatic Climate Controls
HEATER AND A/C CONTROL ASSEMBLY
Description
The Heater And A/C Control Assembly is the control component of the Electronic Climate Control System.
Operation
It receives inputs from the In-Car Temperature Sensor, Ambient Temperature Sensor, and the selected temperature setting. In AUTO, the Heater
And A/C Control Assembly determines the Blower speed and the Air Mix Valve position. It also determines whether the compressor must come
on to reach the desired temperature.
When the system is in AUTO, air is discharged through the floor outlets when the car is being warmed, and through the Instrument Panel (I/P) and
floor outlets when the car is being cooled. A mode may also be selected manually by pressing any other mode button.
ELECTRONIC CLIMATE CONTROL (ECC) PROGRAMMER
Description
The ECC programmer directs the flow of air to the proper outlets by controlling the operation of three Vacuum Actuators with four Valve
Controls.
Operation
When a Valve Control is energized, vacuum is applied to a Vacuum Actuator, causing a valve to move.
The ECC Programmer also contains a Programmer Motor Assembly and Air Mix Valve Position Potentiometer. The Programmer Motor directs
the air flow through the Heater Core or the A/C Evaporator Core. By changing the polarity of the voltage applied to it, the motor can be operated
in either direction. The Heater And A/C Control Assembly uses the Air Mix Valve Position Feedback to calculate Air Mix Valve positioning.
