1978 Ford FiestaFACTORY OEM SERVICE PROCEDURE

Electronic Control Module

Each module uses 6 or 7 wires. The Blue wire, if equipped, is a fusible link that protects the electronic control module. The Red and White wires are ignition feed. The White wire is ignition primary circuit while engine is cranking, the Red wire is ignition primary circuit while engine is running. The Red wire contains the ballast resistor.

The primary current is turned on and off by the electronic control unit through the Green wire between module and coil. The Orange and Purple wires (Violet wire on AMC) transmit signals to the module from the distributor stator/magnetic pick-up coil. The Black/Green wire (Black wire on AMC) is the distributor ground circuit.

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

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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.