Trail lights and reverse lights not working

How about the headlights and running lights? Brake lights? You said fuses look good, how about relays?

My headlights, running lights, fog lights, brake lights and flashers all work.. Tried changing turn signal switch, and that wasn't it.. Tried changing headlight switch, that didn't work either.. checked plug under truck, that looked good..Where are the relays?

Engine compartment fuse box

It should be on driver side.....there are also fuses in there that control issue lights too so might look those over too

Also note you'll have some extra fuses for this if it has the tow package installed. And you may want to inspect the wiring if all of those +relays are good since it is both sides. Doubly so if you have a tow package.