Blair

You are correct in that you do not have to splice into the low-beam
wire, you can get that signal from any 12V source you like as that is
only the trigger signal for the relay. A couple of cautions though if
you are considering using a different source. First, use a switched
circuit so that you cannot accidentally leave your fog lights on when
leaving the truck, unless you want that ability. Second, it may be
illegal in your location to burn the fog lights with anything except
running lights and/or low beams on, check with your local state patrol
or DMV for this.

Next, you may not need to mount this switch. On most (notice I did not
say ALL) Rams (mainly SLT and above I believe) Dodge pre-wired for fog
lights. Look behind the front bumper on the drivers side around where
the fog light mounts. If you see a harness with an open plug, you are
pre-wired and your install just got a whole lot easier. You can go to
www.dodgeparts.com and order the headlight switch with fog light feature
($40.05) and a wiring harness ($28.16) that will allow you to do exactly
what you are wanting, a factory appearing fog light install.

For more discussions on this install and a complete wiring diagram,
check out www.dodgetruckworld.com.

I do not know if this install will work without the pre-wiring
installed. That is what I am facing on my 2004 ST model.

Good luck!
Rob