Ignition Switch

Replace the ignition switch on a 1972 Ford F-100 with 302ci V8, accessed from under the dashboard behind the steering column.

Warnings

Tools required

Parts

• Ignition switch × 1 — Use OEM specification
• Wire connector set (if harness damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and engage parking brake
2. Disconnect negative battery cable and secure away from terminal
3. Allow sufficient time for any residual electrical charge to dissipate (5 minutes minimum)
4. Position yourself under dashboard with adequate lighting to view steering column
5. Verify replacement ignition switch matches original configuration

Procedure

1. 1

   Access the ignition switch
   Working from under the dashboard, locate the ignition switch. On 1972 F-100 trucks the switch may be mounted either on the steering column or on the instrument panel depending on configuration; verify your vehicle's arrangement. The switch has a multi-wire connector harness attached.
2. 2

   Document electrical connections
   Before disconnecting, note the wire colors and their positions on the ignition switch connector. The typical configuration has multiple wires that may include battery feed, accessory, ignition, and start circuits. Wire colors vary by production date - carefully document the actual wire colors and positions on your specific vehicle. Take a photo or draw a diagram for reference during reassembly. Verified detail (1972 Ford ignition switches typically use more than 4 wires (battery, accessory, ignition/run, start, plus often a resistor/coil feed and ground). The specific wire colors listed are not verified for Ford factory color codes and may mislead reassembly. Rely on documenting actual wire positions rather than assumed colors.): Before disconnecting, note the wire colors and their exact positions on the ignition switch connector, as Ford switches of this era may have 5 or more wires (battery, accessory, ignition/run, start, and coil/resistor feed). Do not rely on assumed color codes; document the actual wiring on your vehicle. Take a photo or draw a diagram for reference during reassembly.
3. 3

   Disconnect electrical connector
   Press the locking tab on the electrical connector and carefully pull it straight off the ignition switch terminals. If connector is corroded or difficult to remove, use needle-nose pliers to gently work it free, being careful not to damage wires.
4. 4

   Remove steering column cover (if equipped)
   If your F-100 has a lower steering column cover, remove the retaining screws securing it and set aside. Not all 1972 F-100 models have this cover - skip this step if yours does not.
5. 5

   Position lock cylinder for switch removal
   The actuating rod position will be set during installation. You do not need to manipulate the key position for switch removal on this vehicle. This aligns the actuating rod with the ignition switch and allows switch removal. Do not turn to START position.
6. 6

   Remove ignition switch mounting fasteners
   Locate the mounting fasteners securing the ignition switch to the steering column (typically 2 screws, though type and count vary). Remove the fasteners completely and retain for reinstallation.
7. 7

   Separate switch from actuating rod
   Carefully pull the ignition switch away from the steering column while simultaneously disengaging it from the actuating rod that connects to the lock cylinder. The rod slides out of a slot in the back of the switch. Note the orientation of the switch and rod connection for proper reinstallation.
8. 8

   Inspect actuating rod and column
   With switch removed, examine the actuating rod for wear, bending, or damage. Check the mounting surface on the steering column for cracks or stripped screw holes. The rod should move freely when the key cylinder is turned. Replace rod if worn or bent.
9. 9

   Prepare new ignition switch
   New ignition switches typically include a plastic shipping pin that holds the switch in the correct position for installation. Leave this pin in place until after the switch is mounted to the column - it will be removed later. Verify the internal contacts match the original switch configuration and that the actuating rod slot is properly oriented.
10. 10

    Install new ignition switch
    Turn the lock cylinder to the LOCK position. Align the new ignition switch (with shipping pin still installed) with the actuating rod and slide the rod into the slot on the back of the switch. Position the switch against the steering column mounting surface, ensuring proper alignment with the screw holes.
11. 11

    Secure ignition switch
    Install the 2 mounting screws and tighten firmly by hand using a screwdriver. Do not overtighten as this may crack the switch housing or strip the column threads. Screws should be snug with no switch movement.
12. 12

    Reconnect electrical connector
    Align the electrical connector with the ignition switch terminals according to your documentation from step 2. Push the connector firmly onto the switch until the locking tab clicks into place. Verify all wire terminals are fully seated.
13. 13

    Reinstall steering column cover
    If removed in step 4, reinstall the lower steering column cover and secure with the 2 screws. Ensure no wires are pinched between the cover and column.

Reassembly

1. Reconnect negative battery cable to battery terminal
2. Ensure all tools and parts are removed from under dashboard before testing

Verification

• With brake pedal depressed, turn key to RUN position - dash warning lights should illuminate
• Test accessory position (first key position) - radio and accessories should power on with engine off
• Turn key to START position - engine should crank and start normally
• Verify key returns to RUN position automatically after releasing from START
• Test that key can be removed only in LOCK position
• Check that all electrical accessories function normally in each key position
• Verify no warning lights remain illuminated with engine running

More procedures for this vehicle