From what I saw, what we usually refer to as the round factory fog lights are wired into the Tailight circuit through the Taillight relay and the "Tail/Illum Light" 15amp CB-5 fuse in the dash.

But that fuse and relay would only come into play if the lights are still wired on that circuit. From the sound of it though, you say they were wired separately when you had the aftermarket LED fogs installed? If that's the case, only your installer would know where he decided to get the source power and whether he utilized the factory taillight relay (most aftermarket fog light setups come with their own wiring including a relay and fuse holder), but you could just follow the wiring routed from the switch in the 3 button panel you put in the fuzzy hole and see where it goes. Since you may not be dealing with the factory setup, that might be your only option anyway.

Couldn't hurt to double check CB-5 first though. I know I've used the factory wiring harness for aftermarket setups in the past anyway (including fog lights and horns), so it may be something that simple.