1977 Ford Bronco Automatic TransFACTORY OEM SERVICE PROCEDURE

Electronic Control Module

The module uses 6 wires. The Red and White wires are ignition feed. The White wire is ignition primary circuit with engine cranking and Red is ignition primary (1.35 ohms resistance) with engine running. The primary current is turned on and off by the control unit through the Green wire between module and coil. The Orange and Purple wires transmit signal to the module from the distributor stator/magnetic pick-up coil. The Black/Green wire is the distributor ground circuit.

Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.