HVAC System - Manual

A single front auxiliary HVAC control module located over the Instrument Panel (IP) controls the cargo van's auxiliary A/C air delivery and temperature controls. Both temperature control and mode control for circulating the inside air is possible. The rear auxiliary mode valve directs air either through the overhead vents or through the lower vents along the left side of the rear compartment. The rear auxiliary temperature valve directs the air flow either through or around the heater core in the rear auxiliary ventilation system. Electric motors control the positions of both valves. Both the rear auxiliary mode valve and seal assembly and the rear auxiliary temperature valve assembly receive operating voltage through CKT 341 (BRN) from RR HVAC fuse 24. This voltage is available only when the ignition switch is in the START position or in the RUN position. Both valve assemblies ground through CKT 150 (BLK) to ground G400. Each valve assembly positions in response to a voltage signal from the rear auxiliary HVAC control module. The rear auxiliary mode valve and seal assembly receives the positioning signal through CKT 733 (LT BLU). The rear auxiliary temperature valve assembly receives the positioning signal through CKT 734 (DK GRN). The rear auxiliary HVAC control module also receives power from RR HVAC fuse 24 through CKT 341 (BRN). The rear auxiliary HVAC control module also grounds through CKT 150 (BLK) to ground G401. In the control module, current flows through 2 parallel rheostats. The temperature control dial moves the wiper arm of one rheostat. The mode control dial controls the wiper arm of the other rheostat. The wipers select a portion of the voltage dropped across each resistance. The connected actuator motor receives this voltage in order to position the valve.