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 offset 2°C (4°F) cooler or warmer than the primary setting. The temperature switches operate independently from each other. To activate the dual zone, the passenger toggles the right air temperature switch to the desired offset. A signal is sent from the HVAC control processor to the right air temperature actuator on the passenger HVAC control assembly circuit. The passenger side temperature will appear on the VF display as a red and blue bar graph. 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 HVAC control processor provides power to the right air temperature actuator through the off/run voltage circuit. Ground is provided by the low reference circuit.

The right air temperature actuator is an electronic stepper motor with feedback potentiometers. 0 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. A 5-volt reference signal is sent out over the 5-volt reference circuit, from the HVAC control processor, to the right air temperature actuator. When a desired temperature offset is selected, whether manual or automatic, the solid state circuit is used to determine the right air temperature door position signals value. A separate 5-volt reference is sent from the HVAC control processor to the solid state circuit. The HVAC control processor software uses this reference voltage to determine the right air temperature actuators position through the right air temperature door position signal circuit. The motor moves the right air temperature actuator door to the desired position.