Ignition Coil - Single

This procedure covers the removal and replacement of the ignition coil on a 1972 Ford F-100 with a 302ci V8 engine, including disconnecting the battery, removing electrical connections, and installing a new coil.

Warnings

Tools required

Parts

• Ignition coil × 1 — Use OEM specification or aftermarket equivalent rated for points or electronic ignition as equipped

Preparation

1. Park the vehicle on level ground and engage the parking brake
2. Turn off the engine and remove the key from the ignition
3. Allow the engine to cool if it has been running recently
4. Open the hood and secure it in the raised position

Procedure

1. 1

   Disconnect the battery
   Disconnect the negative battery cable from the battery terminal using a 1/2" wrench. Move the cable away from the battery post to prevent accidental contact during the repair.
2. 2

   Locate the ignition coil
   The ignition coil is typically mounted on the intake manifold near the front of the engine, or on the engine or a nearby bracket. It is a cylindrical canister-style coil with two primary wire terminals and a single high-tension tower for the distributor wire. It is a cylindrical canister-style coil with two primary wire terminals and a single high-tension tower for the distributor wire. Verified detail (On the 1972 Ford F-100 with 302ci V8, the ignition coil is typically mounted on the driver's side (left side) of the engine, not the passenger side. This is standard for small-block Ford V8s of this era.): The ignition coil is mounted on the driver's side of the engine, typically on the intake manifold or firewall.
3. 3

   Disconnect the high-tension lead
   Grasp the rubber boot on the high-tension (coil) wire that connects the coil tower to the distributor cap. Pull the boot straight off the coil tower. Do not pull on the wire itself, only the boot.
4. 4

   Disconnect the primary wires
   Using a 7/16" wrench, loosen and remove the nuts securing the two primary wires to the coil terminals (positive and negative). Note the position of each wire: the positive wire typically connects to the terminal marked '+' or 'BAT', and the negative wire connects to the terminal marked '-' or 'DIST'. Remove the wires and set them aside.
5. 5

   Remove the coil mounting hardware
   Remove the bolt(s) securing the coil bracket to the intake manifold or mounting location using a 7/16" socket or wrench. If the coil is mounted in a bracket, remove the bracket with the coil attached, or remove the coil from the bracket first depending on access.
6. 6

   Remove the ignition coil
   Lift the ignition coil out of the engine compartment. If the coil is mounted in a separate bracket, remove the coil from the bracket by loosening the bracket clamp or bolts.
7. 7

   Clean the mounting surface
   Use a wire brush to clean the mounting surface on the intake manifold or firewall where the coil bracket mounts. Remove any corrosion, dirt, or debris to ensure a clean, secure mounting surface for the coil bracket.
8. 8

   Install the new ignition coil
   Position the new ignition coil in the mounting bracket if applicable, then position the assembly onto the engine in the original mounting location. Ensure the coil tower faces toward the distributor for proper wire routing.
9. 9

   Install the coil mounting hardware
   Install the mounting bolt(s) through the coil bracket and thread them into the intake manifold or mounting location. Tighten the bolts snugly by hand, then firmly with a 7/16" wrench. Do not overtighten as this can crack the coil case.
10. 10

    Reconnect the primary wires
    Reconnect the two primary wires to the correct coil terminals: positive wire to the '+' or 'BAT' terminal, and negative wire to the '-' or 'DIST' terminal. Install the terminal nuts and tighten with a 7/16" wrench until snug. Do not overtighten.
11. 11

    Reconnect the high-tension lead
    Push the high-tension wire boot firmly onto the coil tower until it seats completely. Apply a small amount of dielectric grease inside the boot if available to prevent moisture intrusion and corrosion.
12. 12

    Reconnect the battery
    Reconnect the negative battery cable to the battery terminal and tighten the terminal nut with a 1/2" wrench.

Reassembly

1. Ensure all electrical connections are tight and properly routed away from hot engine components
2. Verify the high-tension wire is fully seated on both the coil tower and distributor cap

Verification

• Start the engine and verify it runs smoothly without misfiring or hesitation
• Listen for any abnormal arcing sounds from the coil area which would indicate a poor connection
• With the engine running, visually inspect the coil and connections for any signs of arcing or sparking
• Test drive the vehicle to confirm normal acceleration and engine performance under load

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