Dual Zone Control Switch

The right air temperature switch is provided to allow the passenger to offset air discharge temperatures on the right side of the vehicle. Passenger temperatures can be set anywhere between 16°C (60°F) to 32°C (90°F). The temperature switches operate independently from each other. For best results, the passenger offset should only be 2°C (4°F) cooler or warmer than the primary setting. To activate the dual zone, the passenger either presses on or turns the right air temperature switch to the desired offset. A signal is sent from the HVAC control module to the right air temperature actuator on the auxiliary air temperature door control circuit. The passenger side temperature will appear on the VF display to show the desired temperature. Temperature offset will be allowed as long as the driver set temperature is not in maximum hot or cold. If the right air temperature switch has been turned on, it can be turned off by pressing the right air temperature switch. Greater sunload on one side of the vehicle may cause the discharge air temperatures to be different, even when the HVAC system is not operating in a dual zone mode.

The rear fuse block provides power to the right air temperature actuator through the ignition 3 voltage circuit. Ground is provided by the low reference circuit, the HVAC control module and ground circuit. Power and ground are provided to the HVAC control module by the underhood fuse block on the battery positive and ground circuit.

The right air temperature actuator is an electronic stepper motor with feedback potentiometers. Zero volts drives the actuator in one direction while 5 volts moves the actuator in the opposite direction. When the actuator receives 2.5 volts, actuator rotation stops. When a desired temperature is requested, a signal is sent from the HVAC control module to the right air temperature actuator on the auxiliary air temperature door control circuit. A 5-volt reference signal is sent out over the 5-volt reference circuit, from the HVAC control module, to the right air temperature actuator. When a desired temperature setting is selected, whether manual or automatic, the logic circuit is used to determine the right air temperature door position sensor signals value. A separate 5-volt reference is sent from the HVAC control module to the logic circuit. The HVAC control module software uses this reference voltage to determine the right air temperature actuator position through the auxiliary air temperature door position signal circuit. The motor opens the air mixture door to a position to divert sufficient air past the heater core or evaporator to achieve the desired vehicle temperature.