HID Ballast

This procedure covers the removal and replacement of a defective HID ballast on a 2023 Chevrolet Bolt EUV, including proper handling of high-voltage components and connector service.

Warnings

Tools required

Parts

• HID Ballast (xenon headlight control module) × 1 — Use OEM specification for left or right side as needed
• Dielectric grease packet × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn off all electrical accessories and remove key fob from vehicle
3. Access the 12V battery in the rear cargo area by removing cargo floor cover
4. Disconnect the negative terminal of the 12V battery and isolate cable
5. Wait minimum 5 minutes to allow capacitors in HID system to discharge
6. Open hood and secure with prop rod

Procedure

1. 1

   Access the headlight assembly
   Depending on which side ballast is being replaced, turn the steering wheel fully in the opposite direction to gain access to the wheel well. Remove the inner fender splash shield fasteners (push pins and screws) to expose the rear of the headlight assembly. You may need to remove only a portion of the shield for access.
2. 2

   Locate the HID ballast
   Identify the HID ballast module mounted to the rear of the headlight assembly or on the inner fender area. The ballast is a rectangular metal or plastic housing with electrical connectors and a mounting bracket. Use a work light to clearly see the mounting configuration.
3. 3

   Disconnect HID ballast electrical connectors
   Carefully disconnect the input power connector from the vehicle harness and the output connector to the HID bulb. Press the locking tab on each connector and pull straight out with steady pressure. Do not pull on wires. Inspect connectors for corrosion or damage.
4. 4

   Remove ballast mounting fasteners
   Remove the bolts or screws securing the ballast to its mounting bracket or headlight assembly. Most ballasts use either bracket bolts or module mounting bolts. Keep fasteners organized for reinstallation.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)

   Module Mounting Bolts8 Nm (6 lb-ft)
5. 5

   Remove the defective ballast
   Carefully extract the ballast from its mounting location. Be aware of any additional clips or tabs that may be holding it in place. Avoid dropping the ballast as it may contain hazardous materials.
6. 6

   Prepare the new ballast for installation
   Remove the new ballast from packaging and verify it matches the removed unit exactly. Check that all mounting points and connector types align. If the ballast has a ground wire, ensure it is properly positioned for connection.
7. 7

   Install the new ballast
   Position the new ballast in the mounting location, ensuring any alignment pins or tabs are properly seated. If a ground connection is present, clean the contact surface with a wire brush or contact cleaner before connecting. Install and torque mounting fasteners.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)

   Module Mounting Bolts8 Nm (6 lb-ft)

   Ground Bolt14 Nm (10 lb-ft)
8. 8

   Connect electrical connectors
   Apply a small amount of dielectric grease to the connector terminals if provided. Reconnect the input power connector and HID bulb output connector, ensuring each locks with an audible click. Gently tug on connectors to verify secure engagement.
9. 9

   Reinstall splash shield and reconnect battery
   Reinstall the inner fender splash shield, securing all fasteners and push pins. Return to the rear cargo area and reconnect the negative terminal on the 12V battery. Torque to specification and ensure clean contact surfaces.
   ⚠Do not overtighten battery terminal bolts. Specified torque is critical to prevent damage to terminal threads.
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
10. 10

    Test HID headlight operation
    With the vehicle in park and key fob present, turn on the headlights and verify the replaced HID lamp illuminates properly. HID lamps may take 5-10 seconds to reach full brightness and may flicker briefly during warm-up. Check that both low and high beams function correctly.

Reassembly

1. Ensure all connectors are fully seated and locked
2. Verify splash shield is properly secured and not interfering with tire movement
3. Reinstall cargo floor cover over 12V battery compartment
4. Return steering wheel to center position

Verification

• Start the vehicle and verify no warning lights appear on the instrument cluster
• Test headlight operation in all modes (low beam, high beam, daytime running) multiple times
• Observe HID lamp for proper color temperature and steady operation after warm-up period
• Visually inspect for any light leakage or condensation in headlight assembly
• Test-drive vehicle at night to verify proper headlight aim and function

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