Control Assembly: Description and Operation
DUAL ZONE CONTROL SWITCHThe 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 3°C (6°F) cooler or warmer than the primary setting. To activate the dual zone, the passenger turns the right air temperature switch to the desired offset. Temperature offset will be allowed as long as the set temperature is not in maximum hot or cold settings.
The instrument panel fuse block provides power to the right air temperature actuator through the ignition 3 voltage circuit. Ground is provided by the HVAC control module and ground 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 module, to the right air temperature actuator.
When a desired temperature 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 module to the solid state circuit. The HVAC control module software uses this reference voltage to determine the right air temperature actuators position through the right air temperature door control circuit. The motor moves the right air temperature door to the desired position. Ground for the right air temperature actuator are provided by the low reference circuit and HVAC control module.