How to Fix My Flickering HID Headlights

High Intensity Discharge (HID) headlights receive power from a ballast, which moderates the amount of current getting to the HID headlight. In all, there are four main components on an HID headlight circuit: the HID headlight bulb, the wiring harness connecting the HID to the ballast, the ballast itself and the wiring harness connecting the ballast to the vehicle's battery. Any one of these elements may be the cause of your flickering HID headlight bulbs. Fortunately, troubleshooting to discover which is the problem is a straightforward task.

• 1

  Replace the HID headlight bulb. Turn off the vehicle, prop open the hood, disconnect the wiring harness from the rear headlight assembly, remove the HID headlight bulb and insert a replacement. Test the HID headlight to see if it no longer flickers. Continue to the next step if it does.

• 2

  Replace the wiring harness that connects the HID headlight to the ballast. Pull the wiring harness off the rear of the HID headlight and the side of the ballast and install the replacement. Turn the vehicle back on and check whether the HID headlight still flickers. Continue to the next step if it does.

• 3

  Replace the ballast. Turn the vehicle off and disconnect the two wiring harnesses from the side of the ballast and connect them to the replacement ballast. Check whether the HID headlight turns on now without flickering. Continue to the next step if it does.

• 4

  Replace the wiring harness from the ballast to the power distribution center. Disconnect the wiring harness from the ballast to the distribution center and connect the replacement to the ballast and the distribution center. Turn the HID headlight on again and verify that it no longer flickers.