This procedure covers the removal and replacement of the HID ballast module on a 2021-2024 Ford F-150 with 3.5L EcoBoost engine, including proper electrical disconnection and testing.

Warnings

Tools required

Parts

• HID ballast module × 1 — Use OEM Ford specification for correct voltage
• Dielectric grease × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn headlights off and remove key from ignition
3. Open hood and secure with prop rod
4. Allow HID system to cool for at least 10 minutes if vehicle was recently operated
5. Disconnect negative battery terminal and wait minimum 2 minutes for capacitor discharge
6. Identify which side requires ballast replacement (driver or passenger)

Procedure

1. 1

   Disconnect battery negative terminal
   Using a 10mm socket, loosen the negative battery terminal bolt. Remove the cable from the battery post and secure it away from the terminal to prevent accidental contact. Wait a minimum of 2 minutes for the HID ballast capacitors to fully discharge.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
2. 2

   Access headlight assembly area
   Locate the headlight assembly on the affected side. The HID ballast is mounted behind the headlight assembly in the engine bay. On the driver side, you may need to move some wiring harnesses aside for better access. On the passenger side, the air intake duct may partially obstruct access but removal is typically not required.
3. 3

   Locate HID ballast module
   The HID ballast is a rectangular metal module approximately 4x6 inches, mounted to a bracket behind the headlight assembly. It will have two electrical connectors: one high-voltage connector going to the HID bulb and one low-voltage power connector from the vehicle harness. Note the orientation and routing of all wiring before disconnection.
4. 4

   Disconnect ballast electrical connectors
   Disconnect the low-voltage power connector from the ballast first by pressing the release tab and pulling straight away from the module. Next, disconnect the high-voltage output connector going to the HID bulb by releasing its locking mechanism (typically a rotating collar or squeeze-tab design). Handle the high-voltage connector carefully and do not allow it to contact metal surfaces.
   ⚠Even with battery disconnected, residual high voltage may be present. Do not touch internal contacts of the high-voltage connector.
5. 5

   Remove ground connection if present
   Some ballast installations include a dedicated ground strap from the ballast to the chassis. If present, use an 8mm or 10mm socket to remove the ground strap bolt. Clean the contact surface on both the ballast and chassis mounting point with a wire brush to ensure proper electrical contact during reinstallation.
   Torque spec

   Ground Strap Bolt16 Nm (12 lb-ft)
6. 6

   Remove ballast mounting bolts
   The HID ballast is typically secured with two or three mounting bolts to a bracket. Using an 8mm socket, remove all mounting bolts securing the ballast to its bracket. Support the ballast with one hand while removing the final bolt to prevent it from falling.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
7. 7

   Remove old ballast
   Carefully extract the ballast from its mounting location, taking care not to snag any remaining wiring. Inspect the mounting bracket for damage, corrosion, or loose bolts. Clean the mounting surface if corrosion is present. Verify the new ballast matches the old unit in size, connector types, and mounting hole locations.
8. 8

   Install new HID ballast
   Position the new ballast in the mounting bracket, aligning all mounting holes. Ensure any integrated ground tab on the ballast makes contact with clean metal on the bracket. Thread in all mounting bolts by hand first to ensure proper thread engagement, then tighten in a cross-pattern to the specified torque.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
9. 9

   Reconnect ground strap if applicable
   If a separate ground strap was removed, reattach it to both the ballast and chassis ground point. Ensure both contact surfaces are clean and free of paint or corrosion. Tighten the ground strap bolt to specification, ensuring secure electrical contact.
   Torque spec

   Ground Strap Bolt16 Nm (12 lb-ft)
10. 10

    Reconnect electrical connectors
    Apply a small amount of dielectric grease to the terminals of both connectors to prevent corrosion and ensure proper contact. First, connect the high-voltage output connector to the HID bulb, ensuring it locks securely (you should hear or feel a positive click). Then connect the low-voltage power input connector from the vehicle harness, again ensuring it locks fully into place.
11. 11

    Secure wiring harness
    Route all wiring away from hot engine components, sharp edges, and moving parts. Ensure wiring follows the original routing path and is secured with any factory clips or tie-downs that were removed during disassembly. Verify no wires are pinched or under tension.
12. 12

    Reconnect battery
    Reconnect the negative battery terminal to the battery post. Clean the battery post and cable terminal if corrosion is present. Tighten the terminal bolt to specification, being careful not to overtighten as this can damage the battery post or terminal.
    ⚠Do not overtighten battery terminal bolts. Excessive torque can crack the battery post or strip the terminal threads.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Verify all electrical connections are fully seated and locked
2. Ensure no tools or parts were left in the engine bay
3. Confirm wiring harness routing matches factory configuration and is secured properly

Verification

• Turn the ignition to the ON position without starting the engine. The HID system should perform a self-test (some flicker is normal during warm-up)
• Start the engine and turn on the headlights. Verify the affected HID headlight illuminates and reaches full brightness within 10-15 seconds
• Check for any error messages or warning lights on the instrument cluster related to the lighting system
• Verify proper headlight aim has not been disturbed. Adjust if necessary using the headlight adjustment screws
• Turn headlights off and on several times to confirm reliable ignition and no flickering after warm-up period
• If available, use a multimeter to check for proper voltage at the ballast power connector (should show battery voltage with headlights on)

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