I am installing a set of PIAA 90 pro lights and I need to take a lead off of one of the stock fog light power wires. I am doing this so that the stock fog light switch can be my master fog light switch. My question is... are both wires that are down by the stock fog light bulbs positive? They are both black. I am talking about right where the plug is that plugs into the actual stock fog bulb. Which one do I tap into to get power when the stock fog switch is on? Is there an easier place to get to the stock fog light wires to do this?