Operation CHARM: Car repair manuals for everyone.

Blower Fan Speed Control System

BLOWER FAN SPEED CONTROL SYSTEM





When AUTO Switch is ON

(a) The desired temperature is set using the TEMP switch.

(b) From the input signals (room temperature sensor, ambient temperature sensor and solar sensor) and the temperature setting, the air conditioner control ECU determines the air flow volume and outputs signals to the power transistor.

(c) When it receives signals from the ECU, the power transistor increases or reduces the blower motor speed to control the air flow volume.

When AUTO Switch is OFF

The ECU turns the power transistor or the extra high relay ON/OFF, increasing or reducing the blower motor speed and fixing the air flow volume in accordance with the position of the Manual switch.