On the quad light setup I had a issue where if the Truck was off the lights would work and I could start the truck after the lights were on for them to stay on. If I turned the lights on after the truck was running I would get a flicker and no lights.
To resolve this I purchased a Capacitor/Relay setup which ran power from the battery, and used the driver side low beam plug to power the relay. I got the relay harness from www.turnagainhighlights.com
and my HID kit from www.hidsource.com
(because of pricing).
This resolved the issue I had.
Most common mistake when installing HIDs I saw was the ballast plug being plugged in wrong.
Hope this helps