Bonneville V6-3.8L SC VIN 1 (1995)
Blower Motor: Description and Operation
Automatic Climate Controls
DESCRIPTION
Blower motor speed is controlled by the solid state blower control module, which follows commands from the Heating Ventilation and Air
Conditioning (HVAC) programmer. The HVAC programmer, in turn, determines the proper blower speed using information from the Heater and A/C
Control, its network of sensors, and the steering wheel controls (if equipped).
OPERATION
The HVAC programmer's blower speed command to the blower control module is a Pulse Width Modulating (PWM) voltage. The blower module
reads the PWM from the programmer and translates that into a D/C voltage between 4 (low blower) and 12 (high blower) volts to the blower motor.
The blower can be operated in either manual fan mode or AUTO fan mode. In manual fan mode, six different fan speeds are available and, once
selected, fan speed remains constant until a new speed is selected from the heater and A/C control or steering wheel controls (if equipped).
In AUTO fan mode, blower speed is infinitely variable (between the minimum and maximum speeds) and varies automatically according to conditions
monitored by the HVAC programmer's network of sensors. Sensors that provide information that may affect blower speed in AUTO mode include: the
in-vehicle temperature sensor, ambient temperature sensor, solar sensor, coolant sensor and vehicle speed sensor.
