On behalf of every other driver out there, please don't do this. Fog lights are down low to the ground and actually point slightly up, if they are installed properly. For everyone else on the road, this is almost the most annoying thing on the face of the planet, and it may be illegal depending on your local regulations. If it isn't, it ought to be. I really think this is dangerous to other drivers.
If you want more light out the front, get some grille lights and tie them in to your highbeams, or get some KC roof-rack lights.
The other side of that coin (and the reason why fog lights are low and pointed up) is that if you need to drive in early-morning fog, such as on an early camping trip, you want the light as close to the road surface as possible. I'm not an electrical engineer, but it looks like this relay will ensure that if you independently turn on your fogs, your high-beams will come on, thus scattering a ton of light into the fog and blinding you.
I don't know about the newer Rangers, but on the 95 I looked at, you could turn on the parking lights and fog lights, the headlights and fog lights or the highbeams alone. Leaving the fog light switch on all the time cut the fogs on and off with the headlights or parking lights.