With Electronic Climate Control

The blower control module is a solid state device that operates the blower motor. The blower control module outputs a voltage that varies between 0 volts (blower motor OFF) and 12 volts (maximum blower motor speed).

To determine the appropriate output voltage, the blower control module monitors a varying voltage signal (between about two and eight volts) from the heater and A/C programmer. The module then amplifies the signal and applies voltage directly to the blower motor. Blower control module output voltage is also monitored by the heater and A/C programmer.