Hi folks,
No back-up lights, left half of the trunk lid lights are out and the rest are dim, including the license plate lights. No blown fuses, and the bulbs test okay. No signs of damaged wire harness or corroded connections. Thoughts appreciated. Jim

the first place I would look is where the wiring harness follows the truck hinge on p side wires are bad to break over time in that area check for breaks in the wires. make sure in that area

Thanks for the tip Boss, it was spot on. While the harness looked okay, I found a broken ground wire inside, just where the harness split off to feed the trunk lid lights. Spliced same and adjusted the harness location. Good to have the lights back on.
Jim

Thanks for letting us know what fixed it!