Fog Light Wiring

Using a relays will be your best bet. I'm not sure if they make them but I think they do. You'll need a normal relay(normally open contacts) and you'll also need on with normally closed contacts. Tie the NO relay to the hot going to the low beam lights so when you turn them on the fog lights come on. Tie the NC relay to the high beams and put it in line with the NO relay. If you wire it this way when you turn your low beams on the NO relay will close and power will flow thru you NC and your NO then when you turn your high beams on the NC relay will open up and kill power to the fog lights.