If you do not mod the switch you can shorten the life of the HIDs by doing what is called a "Hot Strike". That is re-lighting the HID before is cools, this dramatically reduces HID life. Like when you "flash" the high beams, the lows would shut off and hot strike back on. And of course just switching between them. Cool down time varies, but is generally about 5 minutes. Not to mention that even when off for a short while, like seconds, they take a little time to ignite and come to full brightness. SO if you flash your highs without the mod you would be temporarily blind.