^^^ This ^^^
Nate is right, and you need to disable DRLs on most 08+ WRX's in order to get HID fogs and Low beams to work properly too. Dan (RangeleyRallyDG) had this issue I believe, he informed me so I didn't need to take off the front bumper cover twice. Basically if you leave them plugged in then even the lows and fogs will flicker even because it causes some kind of voltage leak. May not be the case on all models, but this is what we noticed. Like nate said, its a black box, like a relay or something with a one sided wiring harned going in to it. I didn't bother to look in to it, I just unplugged it and rapped the connector in black tape so they would not be exposed to the elements.