The Mayor
+1y
HIDs taking more power to run than stock headlights is a misleading statement. Most HID kits use 30-35 watts to run. A stock headlight bulb will usually be about 50-60 watts. Highbeams, for sake of arguement will be 75 watts. Now, daytime runners will be 25-50% of the voltage, which is why they are dimmer. If you use the 25-50% of 75 watts, you end up with 19-38 watts supplied through the wires. It is the ballast that converts the 30-35 watts to the insane power needed.
This is why some HIDs do not come on unless turned on manually. The HID system may not be getting anywhere near the 30-35 watts needed to run them. IF they blink, it is because the HIDs are getting a close enough voltage to arc, but not maintain that arc.
Another potential problem could be the fact that the insane voltage the ballast is producing is causing interference with a vital circuit or the antenna, akin to running you amplifier power supply too close to your signal wire.
Not trying to sound like a know-it-all, just trying to clarify for those who may be scared off from using HIDs.