I got my cartrimhome lights installed with the ebay switch (linked in my prior post on this thread) over the weekend.
I put the the add a fuse in the open location highlighted by RCO. The diagram is what I used to wire the switch. The green from the switch goes to the add a fuse with the butt splice that is already on the add a fuse. The red 1 goes to the red wire from the light kit with a butt splice from the HF kit. The black is the ground, and I connected to the "alternate ground location" highlighted by RCO for both the black wire from the light kit and the black wire from the switch. I added a terminal ring to each. Actually, the black wire from the switch is too short to reach a convenient ground location, so I had to butt splice in a foot-long wire segment I had from a prior project to make it long enough to reach with the switch in place. I didn't add any relays since the leds are such a small draw, and I used 3 amp fuses. I also learned that the add a fuse I had laying around wouldn't work since the 4Runner uses mini fuses under the dash. Just be warned when you go to buy one. With the add a fuse in place, you can't put the cover back on the under-dash fuse bock. I put it and a selection of mini-fuses together in a zip lock and will keep it in the car (under my newly installed sliding tray).
The fourth red wire from the switch hasn't yet been wired to anything. That would light up the symbol on the switch, so I need to connect that to the 7.5 amp panel light in the fuse box with another add a fuse, I believe, so I can dim it with the other panel lights. Alternatively, I think I could probably just put my current add a fuse in that location with both red wires and be done. I will play around with that when I get some additional time. My car wiring experience is pretty limited (a couple of fog light additions to prior cars), so if anyone has any better suggestions, I'm all ears!
In the meantime, the crappy dark and sideways picture is of the "on" light for the ebay switch (under the wiper heater switch). I'm happy with the match, but will be happier when it lights up with the panel as a whole.