2002 Toyota Avalon back-up and license plate lights

The back-up lights and license plate light do not work. My mechenic says that there is an open break somewhere in the system and wants to open the electrical loom from the fuse box to the rear so he can check all the (40) wires. He checked the fuse box in the passenger compartment and could not find a blown fuse. Is this where the fuse is located for the lights, or is the fuse located in the box under the hood? He never checked under the hood for a fuse even though the owners manual indicates the running lights fuses are located there.