Blower Control

IHKR1 BLOWER CONTROL







The blower motor receives battery voltage from the blower relay as soon as the ignition is switched to "Run". Blower speed is controlled by controlling the motor ground circuit.

The control module uses a voltage signal from the blower control knob to determine how fast the blower should run. The control module then sends a voltage signal to the final stage unit.

The final stage unit is placed in the blower motor ground circuit and it controls how much voltages applied to the blower motor:
- From the beginning of the wedge through position "1" about 3 V is applied to the blower motor, and it runs at very low speed.
- In position "2" about 4 V is applied, and the motor runs at low speed.
- In position "3" about 6 V is applied, and the motor runs at medium speed.

When the blower control knob is rotated to position "4", a relay inside the final stage unit is energized, connecting the blower motor ground circuit directly to ground through the relay contacts. With battery voltage now applied to the blower motor, it runs at high speed.