Gathering the necessary equipment to add a light bar a la oneofakind's how to, and finding that most installations do not wire the power to switched 12v power. I'd like to wire mine to switched 12v, but I'm unclear as to what my options are in the engine compartment. Is the main power block switched, or a direct connection to the battery? Trying to avoid the switch leaching power while it's parked, and only have power available to the switch when key is turned to accessory. Any suggestions?