Passenger Van Rear Temperature & Mode Controls

The Passenger Van's air delivery and temperature controls operate similarly to that of the Cargo Van. However, in the Passenger Van, two control modules and an additional Heater and A/C Control Logic module are provided.

The Front Auxiliary HVAC Control Module is located over the Instrument Panel while the Rear Auxiliary HVAC Control Module is located overhead behind the front seats.

The Heater and A/C Control Logic Module is located in the overhead just ahead of the Front Auxiliary HVAC Control Module. The Front Auxiliary HVAC Control Module's Blower Motor Switch has an additional Rear CNTL position. With Rear CNTL. selected, control for the rear auxiliary mode doors is from the Rear Auxiliary HVAC Control Module. With the Front Auxiliary HVAC Control Module Blower Motor Switch in any other position, the Rear Auxiliary HVAC Control Module has no control.

Each control module is powered from the RR HVAC Fuse 24 through the BRN (341) wire when the Ignition Switch is in START or RUN. Each control module is also grounded by BLK (1) wires to Ground G400. Each control module has a pair of control rheostats for temperature and mode control. The voltage developed at the wipers of these rheostats is routed to the Heater and A/C Control Logic Module. The DK GRN (734) wires deliver the temperature control signals while the LT BLU (733) wires deliver 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 are then routed through the normally-closed contacts to the valve actuators.

When the Front Auxiliary HVAC Control Module has REAR CNTL selected, a ground path is provided for the Heater and A/C Control Logic Module's relay coil. Since the Heater and A/C Control Logic Module's relay coil has voltage applied through the BRN (341) wire from RR HVAC Fuse 24, current flows through the relay coil, through the LT BLU (203) wire to the Front Auxiliary HVAC Control Module. It then flows through the Rear CNTL contacts in the control module and on to Ground G400. The coil energizes and the contacts change state to connect the positioning voltages from the Rear Auxiliary HVAC Control Module to the valve actuators.