Heating and Air Conditioning: Description and Operation

The air delivery system directs the flow of air from the heater and the air conditioner system.

The heater control amplifier, heater control panel, and water solenoid valve are supplied battery voltage through Fuse 7 when the ignition switch is in its ON (II) position.

The heater control amplifier is grounded at G402 and the mode switches are grounded at G401.

Pushing a mode switch sends a signal from the heater control panel to the heater control amplifier through the ORN/WHT wire. The voltage supplied will vary depending on the switch you select. The heater control amplifier provides a signal to drive the mode control motor. The motor controls the position switches which feed back the position of the motor to the heater control amplifier.

When you push the recirculation button, a ground input signal is sent from the heater control panel to the heater control amplifier through the ORN wire. The heater control amplifier sends a signal to the recirculation control motor. The motor runs until the limit switch sends a signal back to the amplifier. When the amplifier receives this signal, the motor stops.

When you push the fresh button, the ground signal is removed from the heater control amplifier, and a signal is sent to the recirculation control motor. The motor runs in the opposite direction until the limit switch sends a signal back to the amplifier. When the amplifier receives this signal, the motor stops.

When you move the temperature control lever to a new setting, a signal is sent through the GRN/YEL wire to the heater control amplifier. The amplifier sends a signal to the air-mix control motor. The motor runs until the position sensor sends a signal back to the amplifier that the desired position has been reached or the hot or cold limit switch has opened.