HID ballasts are control units which convert your vehicle's 12-volt power to high voltage, to be used by gas discharge xenon bulbs. They have ignitors built in to light up the initial arc, and then advanced digital circuitry is used to monitor the power consumption and resistance, keeping the arc running smoothly without flickering or going out.
All of this is not an easy task, so cheaper ballasts will flicker, go out prematurely, or run with low efficiency and output. At Diode Dynamics, we offer premium HYLUX ballasts, which are based on factory Philips technology. These ballasts are known for their high efficiency and reliability, and overall performance - including no radio interference, and a relatively quick startup time.
If you're looking to replace a dead factory ballast, you can use our D1 series unit, though you may need to splice in your factory wiring to bring power to it. Still, this is an economical option to high-priced dealer replacements!