There is an easier way. Here's what I did, so, I can manually override the switch off.
I ran a power tap from one of the unused 30 amp hots in the underhood fuse panel, ran the circuit to a discrete switch under the dash, (through the sound tube hole) and the tapped the switch output into the positive side of the lamp power, which is just one wire for both. Obviously, I also fused this circuit separately.
Ford switches power when you turn on the high beams say and the fogs go off. My circuit allows me to replace that power and they'll light up any time, anywhere. It is unswitched power so you wouldn't want to forget them and leave them on but, I couldn't find and ign switched source I could rely on for the amperage draw.
2014 Premium GT, SGM, Brembo, Auto, Tech, Comfort, etc. GT500s, Steeda UCA, VMP auto tune, 100 shot on BBR tune, best et: 11.38 at 120.85
2012 GT, Candy Red, Brembo, 3.73, Tech, Comfort, etc. Procal tune, Roush upper, UMI LCAs, Steeda red bracket, GT500s, 28X10X16 Hoosier slicks, best et: 11.91 at 115.23 RIP