New Headlight Bulb not Working? How to Replace a XENON / HID Headlight Ballast.
You’ve got a headlight out, you order and put in a new bulb but the headlight doesn’t work! Your headlight Xenon HID ballast may be broken!
To troubleshoot a bad headlight ballast, simply swap the headlight bulbs between the bad headlight and the good headlight. If the suspected “bad” headlight bulb works in your other headlight and the “good” bulb does not work, then your headlight ballast may be broken.
This video shows the general steps to trouble shoot and replace a Xenon or HID Headlight Ballast.