Heater Mode

When the HVAC system is in the OFF mode, pressing any HVAC switch will activate the automatic HVAC system. The left air temperature actuator is a reverse polarity motor. Each circuit provides both power and ground to the left air temperature actuator. When the actuator is being held in position, both of the left air temperature door control circuits have 12 volts applied to both sides of the actuator motor. This holds the actuator stationary. When a cool temperature is requested, one of the left air temperature door control circuits will ground, driving the left air temperature actuator into the desired temperature mode. When a warmer temperature is requested, the other left air temperature door control circuit will ground. This moves the left air temperature actuator into a new position.

The right air temperature actuator operates the same as the left side. The right air temperature actuator, located in the air temperature actuator assembly, is a reverse polarity motor. Each circuit provides both power and ground to the right air temperature actuator. When the actuator is being held in position, both of the right air temperature door control circuits have 12 volts applied to both sides of the actuator motor. This holds the actuator stationary. When a cooler than set temperature is requested, one of the right air temperature door control circuits will ground, driving the right air temperature actuator into the desired temperature mode. When a warmer than set temperature is requested, the other right air temperature door control circuit will ground. This moves the right air temperature actuator into a new position.