HID Ballast

Replace the HID ballast module that controls the high-intensity discharge headlight operation on the 2018-2024 Honda Accord 1.5L Turbo.

Warnings

Tools required

Parts

• HID ballast module × 1 — Use OEM specification - specific to left or right side

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow headlights to cool completely if recently operated (minimum 15 minutes)
3. Open hood and secure with prop rod
4. Identify which side (driver or passenger) requires ballast replacement

Procedure

1. 1

   Disconnect battery negative terminal
   Locate the battery in the engine compartment. Using a 10mm socket, loosen the negative terminal bolt. Remove the negative cable and secure it away from the battery post to prevent accidental reconnection.
   Torque spec

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

   Remove headlight access cover
   Locate the plastic access cover on the back of the headlight assembly. Rotate the cover counterclockwise approximately 1/4 turn and pull it away from the headlight housing to expose the HID bulb and ballast connector.
3. 3

   Disconnect HID bulb connector
   Locate the electrical connector attached to the HID bulb. Press the release tab and carefully pull the connector straight back from the bulb. Do not twist or bend the connector excessively.
4. 4

   Disconnect ballast input connector
   Identify the main input connector going to the HID ballast (usually a multi-pin connector from the vehicle harness). Press the locking tab and pull the connector straight out from the ballast module. Note the routing of the wiring for reinstallation.
5. 5

   Disconnect ballast output to bulb
   Locate the high-voltage cable running from the ballast to the HID bulb. Press the release mechanism and carefully disconnect this cable from the ballast module. This cable carries high voltage when operating, so handle with care even though the battery is disconnected.
6. 6

   Remove ballast mounting bolts
   Using an 8mm socket, remove the mounting bolts securing the HID ballast to its bracket or the headlight assembly. Most Honda Accord ballasts use 2-3 mounting bolts. Keep these bolts as they will be reused.
   Torque spec

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

   Remove failed ballast
   Carefully maneuver the ballast module out of the engine compartment, noting how it was positioned and any clips or routing channels used. The ballast may be tucked behind other components and require careful angling to remove.
8. 8

   Install new ballast module
   Position the new HID ballast in the same location and orientation as the original. Ensure any mounting tabs or alignment features are properly seated. Thread the mounting bolts by hand to prevent cross-threading, then tighten to specification using a torque wrench.
   Torque spec

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

   Reconnect ballast connectors
   First, connect the high-voltage output cable from the ballast to the HID bulb until it clicks securely. Then connect the main input connector from the vehicle harness to the ballast, ensuring it locks into place. Apply a small amount of dielectric grease to connections if desired for corrosion protection.
10. 10

    Reconnect HID bulb connector
    Attach the electrical connector to the HID bulb, pressing firmly until it clicks and locks. Verify the connector is fully seated and the seal is properly positioned to prevent moisture intrusion.
11. 11

    Reinstall headlight access cover
    Position the plastic access cover over the back of the headlight assembly. Rotate it clockwise approximately 1/4 turn until it locks into place. Ensure the seal is properly seated around the perimeter.
12. 12

    Reconnect battery negative terminal
    Place the negative battery cable back onto the negative post. Using a 10mm socket and torque wrench, tighten the terminal bolt to specification. Ensure the connection is secure but do not overtighten.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Verify all electrical connectors are fully seated and locked
2. Ensure no tools or parts are left in the engine compartment
3. Check that the headlight access cover is properly secured to prevent moisture entry

Verification

• Turn the ignition to ON position (engine can remain off)
• Turn headlight switch to low beam position and verify the repaired HID headlight illuminates within 5-10 seconds (normal warm-up time)
• Switch to high beam and verify proper operation
• Check for any error messages or warning lights on the instrument cluster
• Verify headlight beam pattern is correct and properly aimed
• Observe the headlight for several minutes to ensure the ballast maintains stable operation without flickering or shutting off

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