I'm with carolines truck, use a relay. I wired mine through a relay as well. Mine are turned on with a toggle, but I added an aluminum panel under the dash just for mounting any toggles or cables so that I didn't have to cut up the dash. The toggles for the overdrive, fog lamps, and auxilliary fan all mount on the panel, along with the lockout cable for the overdrive. The fog lamp toggle is powered from the headlamp switch, so if the headlamps are off, there's no power to the fog lamps.
