Originally Posted by Las0mbra
My dual beam kit came with a harness of some sort, so I didn't get it. I just got a 4500k dual beam 9007 kit. (I would have liked 5000k or 6000k though) and it came with this
Yup that's what it all looks like. The reason for the harness is because our cars have one bulb for both high and low beams. Therefore the bi-Xenon bulbs for our cars need the harness which has a relay to focus the beam from low to high.
If you wanted to get HID's for single beam lights like the fog lights they do not require a harness. The factory plug would plug into the ballast and the hid bulb would plug into the ballast and that's it, no harness needed.