General Information

The blower motor forces outside air into the vehicle's interior. The vehicle operator determines the blower motor's speed by toggling the blower motor switch manually or by using the automatic mode.

The blower control module receives power from the fuse block through the battery positive voltage circuit. Ground is provided by the blower control module through the ground circuit.

When any blower speed is selected, whether manual or automatic, a Pulse Width Modulated (PWM) signal is sent from the heater and A/C control to the blower control module through the blower speed circuit. When a low blower speed is requested, the PWM signal is reduced. When a higher blower speed is requested, the PWM signal is increased. A 4 to 12 volt signal is then sent to the blower motor from the blower control module through the motor positive circuit. A signal is delivered back to the heater and A/C control, from the blower control module, through the blower speed feedback circuit to let the heater and A/C control know what speed the blower motor is in. The blower motor is grounded through the motor negative circuit. An open circuit, short to ground or short to battery on the blower speed circuit will disrupt the PWM signal and cause the blower motor to not operate. In automatic operation, the heater and A/C control will determine what blower speed is necessary in order to achieve or maintain a desired temperature. Toggling the blower switch manually also activates the VF display for the blower speed selected.