Yes so if you wire it up so the feed wire for the headlights from the car loom is powering a relay instead of the ballast directly, does the sensor not pick up that it's a lower current because the current used to power the relay is the same as powering a normal halogen bulb?
I would say the way he has wired them up, the go straight from the battery, powering the relay to turn the lights on but bypasses the sensor for the bulbs, until we know how it's done, I can't be too sure! haha
Danny.