I have just installed and HID kit in my car and I have the same problem. My high beams will work but not my lows. I dont know if it is because HID's need more power to the ballasts.....but then again that defeats the purpose of HID's because they are supposed to use less power from the car. Any way...if you look at the connector that hooks up to the light bulb you will notice 2 sets of wires, 2 red wires and 2 black wires. One pair is for lows and one for highs. I would say try a fuse. Because fuses blow to prevent any electrical spiking (increase in voltage) to a electrical device in your car like a light bulb. I am going to go try a fuse right now. As someone stated in a reply "fuses .10 light bulb $what ever autozone charges.00".