back up lights are not working on 2005 Chevrolet Silverado 2500 HD

my backup and dome lights do not work. the bulbs are good, the fuse inside are good. is there another fuse or something else i can check?

The back up light fuse is located in the underhood fuse and relay box. It feeds the lighting control module. Check that fuse first. Beyond that could be a control module issue or a broken wire.