The best thing to do would be to buy a 12v testlight, use that to determine what wire is hot. If you want the fogs to come on with the low beams, tag onto the low beam 12v wire and use that wire to signal/trigger a $2 relay from any parts store. For the relay you will need: B+, B-, your low beam 12v signal wire and the wires (2) going to your fogs that will be grounded at the light. Using the relay you won't overload the headlight circuit, you won't need any wires going inside the car, and you can make it a nice install all located somewhere near the battery that nobody will ever notice. Also the fogs will shut-off when the high beams are on which I THINK is state law in many states. Goodluck