Juice passing by the 15A tail fuse means that the relay and switch are OK. Not getting to the rear lamps and visually inspecting most of the wiring points at two possible failure points. One is the rear junction connector, where all the tail's source voltage gets passed through - actually in an odd place, on my 2002 it is under the center console box. The other possibility is the integration relay, which is a major PITA - but if it was faulty, you should have other lights that don't work (dash warning lamps, etc.).