Ignition Coils - All

This procedure covers removal and replacement of the ignition coil on a 1972 Ford F-100 with 302ci V8 engine, including distributor cap removal and spark plug wire management.

Warnings

Tools required

Parts

• Ignition coil × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake.
2. Allow engine to cool completely if recently operated.
3. Disconnect negative battery cable from battery terminal.
4. Gather all tools and new ignition coil before beginning work.

Procedure

1. 1

   Label and disconnect spark plug wires from distributor cap
   Using masking tape and marker, label each spark plug wire with its cylinder number (firing order is 1-5-4-2-6-3-7-8, with cylinder 1 at front driver side). Remove all 8 spark plug wires from distributor cap by grasping boot firmly and twisting while pulling straight away from cap. Do not pull on wires themselves.
2. 2

   Remove distributor cap
   Remove the 2 distributor cap retaining clips by prying them off with a screwdriver or releasing spring tension. Lift distributor cap straight up and set aside with wires still attached. Inspect cap for cracks, carbon tracking, or corrosion.
3. 3

   Disconnect coil secondary wire
   Disconnect the high tension lead (thick wire) from the center tower of the ignition coil by pulling boot straight out. This wire runs from coil to center of distributor cap.
4. 4

   Disconnect primary wiring from coil
   Locate the two primary terminals on the coil (marked BAT and DIST or + and -). Remove the nuts securing the two primary wires using a 5/16" wrench or socket. The BAT terminal receives power from ignition switch, the DIST terminal connects to distributor points. Remove both wire terminals and note their positions for reinstallation.
5. 5

   Remove coil mounting bracket bolts
   The coil is mounted to either the intake manifold or a firewall-mounted bracket using a U-bracket clamp. Remove the 2 mounting bolts securing the coil bracket using a 7/16" socket or wrench. Support coil while removing second bolt.
6. 6

   Remove old ignition coil
   Lift the coil and mounting bracket assembly away from engine. If bracket is reusable and not damaged, separate coil from bracket by loosening bracket clamp. Inspect mounting area on intake manifold or firewall for corrosion or damage.
7. 7

   Prepare new coil for installation
   Install mounting bracket onto new coil, ensuring bracket is positioned to match original orientation. If coil came with bracket, verify correct terminal orientation (BAT terminal typically faces toward front of engine). Verify new coil is proper 12-volt type for points ignition system.
8. 8

   Install new coil assembly
   Position new coil with bracket onto mounting location on intake manifold or firewall bracket. Start both mounting bolts by hand, ensuring bracket sits flat and coil is oriented with terminals accessible. Tighten mounting bolts securely using 7/16" socket, alternating between bolts to ensure even clamping pressure.
9. 9

   Connect primary wiring to new coil
   Reconnect the two primary wire terminals to correct posts on new coil. BAT terminal (or +) receives the wire from ignition switch (typically red or pink wire). DIST terminal (or -) receives wire from distributor (typically green or black wire). Install terminal nuts and tighten securely with 5/16" wrench. Verify connections are tight and properly oriented.
10. 10

    Reconnect coil secondary wire
    Insert the high tension lead firmly into the center tower of the new ignition coil until boot seats completely. Apply small amount of dielectric grease to inside of boot if available to prevent moisture intrusion and ensure good connection.
11. 11

    Reinstall distributor cap
    Position distributor cap back onto distributor body, aligning cap locating tabs with distributor housing. Secure cap with the 2 retaining clips, ensuring they snap or lock into place firmly. Verify cap is seated completely and cannot be lifted or rotated.
12. 12

    Reconnect spark plug wires to distributor cap
    Reconnect each spark plug wire to its correct distributor cap tower according to labels applied earlier. Press each wire boot firmly onto cap tower until it seats with an audible click. Verify firing order sequence 1-5-4-2-6-3-7-8 is followed in the direction of distributor rotor rotation (counterclockwise on the Ford 302) around the distributor cap. Confirm the number 1 terminal corresponds to the number 1 plug wire before reconnecting remaining wires. Verified detail (The distributor on a Ford 302 rotates counterclockwise, not clockwise. Viewing from above, cylinder 1 position varies by distributor orientation but rotation direction is definitively counterclockwise.): Verify firing order sequence around distributor cap matches 1-5-4-2-6-3-7-8 in counterclockwise direction with number 1 cylinder position marked on distributor cap or housing.
13. 13

    Reconnect battery and verify installation
    Reconnect negative battery cable to battery terminal and tighten securely. Visually inspect all connections at coil, distributor cap, and spark plug wires. Verify no wires are contacting exhaust manifolds or moving engine components.

Reassembly

1. Verify all spark plug wires are firmly seated on distributor cap towers and routed away from exhaust components.
2. Ensure coil mounting bolts are tight and coil cannot move in bracket.
3. Confirm primary wire connections at coil terminals are secure with no exposed bare wire.

Verification

• Start engine and verify it runs smoothly without misfiring or hesitation.
• Check for visible spark arcing around coil tower, distributor cap, or spark plug wire connections - none should be present.
• Listen for abnormal clicking or snapping sounds from ignition system during engine operation.
• With engine at operating temperature, verify smooth acceleration and no stumbling under load.
• If engine fails to start, verify primary wiring polarity is correct (BAT to power source, DIST to distributor).

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