You have a plug in for your fog lights. One should be hot when you turn on you running lights. I would hook into that. I'm not sure what color it is off the top of my head. But if you have a power test light it shouldn't be too hard to find.
I agree, I no longer have the instructions, but I installed one and I remember hooking it into the foglight plug that is not used. Pop out the switch and test light the plug to find the right wire like DJ said.
"I'm not that interesting of a person" -Steve McQueen