'04 Honda Civic tail-light issues

Brake lights and rear turn-signals work, tail-lights and license plate light do not. Fuse not issue. Might I have dislodged or otherwise damaged wire putting 8’ lumber through trunk and over flipped down back seat? Any easy way for the mechanically challenged to figure out what and where problem is or do I need to go to dealer or shop and have them determine?

You could have yanked something loose, of course. Did it stop working after the lumber transport?
Here’s a schematic with pertinent information on how these lights are hooked up. Maybe a common ground is loose, a common wire got yanked loose or it could be the relay I’ve circled in red. Are you comfortable around schematics? If so, you can probably trace the voltage with a test light or multimeter to see where it is missing.

Have you tried replacing the bulbs? The brake lights are dual filament and may just be burnt out. The plate light could be burnt out and you just did not notice and neither did the cops. This would be the best scenario. Wiring would be next.

I recommend you buy a basic circuit tester. It looks like an ice pick with a wire coming out of a transparent handle, and the end of the wire usually has an alligator clip. There is a light bulb inside the transparent handle. This tool can be handy for problems like this.

I would remove the bulbs from the sockets, turn the lights on, and after attaching the alligator clip to a ground, press the tip of the circuit tester against the bulb contacts. If you’re getting power to the socket, the light on the circuit tester will come on. You should also be able to use the circuit tester on the rear end of the light bulb socket, where the wires attach to the socket. This might help you determine if the wires got yanked, breaking the connection between the wires and the socket.

If you’re not getting power to the light bulb sockets, trace the wiring back as far as you can and test the circuit to see if it is getting any power. You can also use the circuit tester at the location where you insert the fuses to see if power is getting to the fuse. Don’t just start yanking fuses out to check them. Identify which fuse controls these lights and test that one only. There is usually a diagram on the inside of the fuse box cover that indicates the function of each fuse.

If the fuse is getting power, but the light bulb socket isn’t, the chance is pretty good (but not certain), that you damaged the wiring with the lumber.

Check to see if the front running lights are working. If they don’t work either I would suspect you missed a bad fuse.

Do a visual of the brake/tail light areas from inside the trunk if you can. You should see wire cables running to each side. I expect the wood bumped something there out of whack. This has happened to me. You’ll likely find something broken or a connector bent or disconnected. You’ll probably have to remove some covers of some sort, the ones you’d remove to replace a bulb. Don’t overlook the ground wire for the tail-light fixture too. It might have broke or come loose. Look for a wire that connects to the chassis in that area.