Passenger Van Rear Temperature And Mode Controls

The passenger van's air delivery and temperature controls operate in a manner similar to the controls of the cargo van. The difference is the passenger van has two control modules and an A/C control logic module.

The front auxiliary HVAC control module is over the IP. The rear auxiliary HVAC control module is overhead behind the front seats. The heater and A/C control logic module is overhead, just ahead of the front auxiliary HVAC control module. The front auxiliary HVAC control module's blower switch has an additional rear CNTL position. With the selection of the rear CNTL position, control of the rear auxiliary mode door is from the rear auxiliary HVAC control module. With the front auxiliary HVAC control module in any other position, the rear auxiliary HVAC control module has no control.

Each control module receives power from RR HVAC fuse 24 through CKT 341 (BRN) when the ignition switch is in the RUN position or the START position. Each control module grounds through CKT 150 (BLK) to ground G400. Each control module has a pair of rheostats for temperature and mode control. The voltage developed at the wipers of these rheostats routes to the heater and A/C control logic module. CKT 734 (DK GRN) delivers the temperature control signals. CKT 733 (LT BLU) delivers the mode control signals. If the front auxiliary HVAC control module is not in the rear CNTL position, the relay in the heater and A/C control logic module remains de-energized. The signals from the front auxiliary HVAC control module then route through the normally-closed contacts to the valve actuators.

When the front auxiliary HVAC control module is in the REAR CNTL position, a ground path is available fro the heater and A/C control logic module's relay coil. Because the heater and A/C control logic module's relay coil receives voltage through CKT 341 (BRN) from RR HVAC fuse 24, current flows through the relay coil, through CKT 203 (LT BLU) to the front auxiliary HVAC control module. Current then flows through the rear CNTL contacts in the control module and continues to ground G400. The coil energizes. The contact change state in order to connect the positioning voltages from the rear auxiliary HVAC control module to the valve actuators.