1994 Ford Bronco/F-Series A/C-Heater Vacuum Routing Diagram - HVAC Hose Colors

This is a scanned page from a 1994 Ford Bronco/F-Series wiring/vacuum reference (labeled "VACUUM") showing the complete vacuum routing for the A/C-heater system. Vacuum is supplied from a manifold fitting (referencing pages 140-1 and 140-2) through a black hose to a vacuum check valve and vacuum tank, then via black hoses through the HVCB (Harness Vacuum Connection Block) and FCCB (Function Control Connection Block) to the A/C-Heater Function Selector Vacuum Valve. The selector valve schematic shows port logic for OFF, MAX, NORM, VENT, FLOOR, FLR/DEF, and DEFROST positions. Color-coded hoses run from the selector: red and yellow to the floor-defrost door vacuum motor, blue to the panel door vacuum motor, and white (through the FCCB and HVCB) to the outside/recirculate door vacuum motor. A cutaway of the HVAC housing shows the heater core, evaporator core, blower motor and wheel, suction accumulator/dryer connection, dash panel, floor-defrost door, panel door, temperature blend door (cable controlled), outside/recirc air door, and airflow paths to defrosters, R & L demisters, floor outlets, and instrument panel registers. A legend defines V = vacuum, NV = no vacuum, PV = partial vacuum. A note directs readers to sections 12-00 and 12-03 of the Service Manual for diagnostics.