Rear running lights not working

Brenden McKay, my name is Alex and I will be helping you today. It sounds to me like you might have a burned out bulb. Here is a helpful link to explain how to track down and fix the problem and some wiring diagrams for your vehicle. Thanks, and let us know if we can help more with this or any other questions you may have. https://www.2carpros.com/articles/no-tail-lights-exterior-running-lights-tail-lights-out

Sorry. Should have included that all of the bulbs are new, as well as both tail light assemblies. I have also checked and replaced the fuse.

Are your license plate lamps working?

No but the upper light above the back window works intermittently

Have you checked the Body Control Module?

I did. Replaced the relays too but still nothing.

Do you have a trailer towing package?

There is a hitch installed but I do not think it is wired for a trailer. I bought it used and the previous owner never used it.

Okay. Have you also checked the stop light switch and splice 311 and 313? You can find these on the original wiring diagram I sent you.