Bonneville V6-231 3.8L VIN 3 SFI (1988)
Control Module HVAC: Description and Operation
Blower Control Module
Blower Motor And Fan
DESCRIPTION
The blower control module contains solid-state circuitry which utilizes a large heat sink positioned in the A/C evaporator air flow. The module
receives command signals from the heater and A/C control assembly, amplifies them, and applies them to the blower motor to vary its speed.
OPERATION
Command signals are based on (1) the blower and mode selections on the heater and A/C control assembly, (2) the set temperature, and (3) the
temperature difference between the in-vehicle temperature and the selected temperature.
With the system in "AUTO," the blower speed increases as the demand to heat or cool the vehicle increases. The automatic blower control is activated
only when the "AUTO" mode button is depressed or after a reset condition occurs (loss of battery power).
If the "FAN" button is depressed, the blower operates in the manual mode until the "AUTO" mode button is depressed or a reset condition occurs.
