1978 Ford Bronco Heater & A/C Duct Diagram - Plenum, Outlets & Control Cables

This document is a labeled line-art illustration (exploded/cutaway perspective view) of the heater and air conditioning air distribution system located behind the instrument panel/dashboard of a vehicle, uploaded as applying to a 1978 Ford Bronco. The drawing shows the plenum chamber, defroster duct assembly, and the ductwork routing air to the various outlets. Eleven callouts identify the major components: the defroster door control arm, center instrument panel outlet, temperature blend door control cable, plenum chamber, defroster duct assembly, right instrument panel outlet, outside–recirculating air door control arm, left instrument panel outlet, temperature control cable, vent–heat door control arm, and floor outlet. From this diagram a reader can learn how the HVAC ducting and control cables/arms are arranged behind the dash, where each air outlet (left, center, right instrument panel outlets and floor outlet) connects, and which control arms and cables operate the defroster door, temperature blend door, outside/recirculating air door, and vent–heat door. The document contains no part numbers, torque specifications, wire colors, or dated applicability information; it is purely an identification/location diagram useful for disassembly, cable adjustment, or component identification during heater/AC service.