Ford Bronco Ignition Circuit Diagram - ICM, Coil, Distributor & EEC-IV PIP/SPOUT

This document is a simplified hand-drawn wiring diagram of a Ford ignition circuit, showing how the ignition control module (ICM), ignition coil, distributor, and EEC-IV engine computer are interconnected. Battery positive power passes through the ignition switch to the ICM and coil. The ICM is drawn with six numbered pins (1, 2, 3, 4, 5, 6): pin 3 receives battery positive, pin 1/2 area connects to ground, and pins 4, 5, and 6 carry the IDM (digital signal), SPOUT, and PIP signals respectively toward the EEC-IV computer, which is shown with pins 4, 36, and 56. The coil is drawn with primary and secondary sides; the primary side receives a switched negative from the ICM, and the secondary side feeds the distributor. Text notes explain the key signals: PIP is a digital pulse output from the distributor to the EEC and ICM indicating the engine is turning; SPOUT is an output from the EEC to the ICM used to advance or retard ignition timing; the IDM signal's function is marked with question marks (unknown to the author). A reader can learn the basic signal flow of the TFI-style ignition system, which module drives coil primary switching, and which EEC-IV pins handle IDM, SPOUT, and PIP.