1987 Ford Crown Victoria & Grand Marquis ATC A/C-Heater Wiring Diagram

This document is a Mitchell Repair Information Company wiring diagram (Fig. 19) for the Automatic Temperature Control (ATC) A/C-heater system on the 1987 Ford LTD Crown Victoria and Mercury Grand Marquis. It shows the complete electrical circuit for the automatic climate control system, including the thermal blower lockout switch, blower motor, ATC function switch (with OFF, VENT, PANEL, HI-LO, FLOOR, MIX, and DEFROST positions), blower switch (AUTO/LO/MED/HI), blower resistors with thermal limiter, ATC servo programmer (M1, M2, HI terminals), clutch cycle pressure switch, electronic control assembly (pins #10, #54, #37), A/C wide-open throttle relay (EFI), throttle kicker relay (carbureted engines), throttle kicker solenoid, diodes, and the A/C compressor clutch. Power feeds come through fuse #9 (BRN-ORG wire) and fuse #6 (WHT-PPL wire). Every wire color code is labeled, e.g., DK BLU-LT GRN, ORG, ORG-BLK, LT GRN-PPL, BLK-YEL, PNK-LT BLU, GRY-YEL, RED-LT GRN, and BLK-LT GRN, and the diagram distinguishes carbureted-only vs. EFI-only branches. A reader can use this diagram to trace circuits, identify wire colors at each component, and diagnose faults in the ATC blower, compressor clutch, and throttle kicker circuits. Printed page dated February 13, 2004; © 2003 Mitchell.