Owner's manual says under the steering wheel but I don't see a compartment anywhere (the center console outlet is dead; I assume it's a fuse).
Google search, found this video, section two, shows cabin fuse box location, tucked up under dash above parking brake. Other helpful advise in video, look up in owner's manual for the right fuse etc. Interior Fuse Box Location: 2004-2009 Toyota Prius - 2005 Toyota Prius 1.5L 4 Cyl. Also.......another search...... This is what the 2007 Prius Owner's Manual (page 435) says about three relevant fuses: 12. ACC-B 25A: "POWER OUTLET", "ACC" fuses 19. PWR OUTLET 15A: Power outlet 21. PWR OUTLET FR 15A: Power outlet