System Precautions

1985 Ford Mustang LX, 2D Hatchback, 5.0 FSECTION System Precautions

Since the electronic control module and ignition coil are "ON" whenever the ignition switch is in the "ON" or "START" position, the system will generate a spark whenever the ignition switch is turned "OFF". This feature may be used as a diagnostic tool to check for continuity of circuit, coil and ignition switch.

Spark may occur if distributor cap is removed with switch "ON". Unless you plan to start engine or perform a test requiring switch to be "ON", keep switch "OFF" during underhood operations. This will prevent accidental engine rotation during service or test procedures.

Silicone dielectric grease must be applied to all insulating areas at distributor, coil and spark plug boots.

A 3/4" clearance must be maintained at distributor cap mounting edge, spark plug wire terminals, and coil tower to prevent high voltage arc to ground.

To help prevent radio frequency interference, coat entire brass rotor tip with silicone dielectric grease to a thickness of 1/32". DO NOT  remove this grease, even if discolored, as grease will maintain its insulating properties.

When removing distributor cap and adapter, DO NOT  remove the cap and adapter as an assembly. Always remove the distributor cap, the rotor, and then the adapter.

RENDER: 1.0x

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When to See a Mechanic

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

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