Tail lights out, but not brake lights

As the title states, I lost my tail lights, side markers, and interior back lighting. Interestingly the gauge lights still work. Brake lights, turn signals, headlights all still work.

At first I thought it might be the trailer I was pulling, and the brake/turn signals still work, but not the clearance/tail lights. I disconnected the trailer, and the problem persisted. Thought it was the fuse, but I swapped it out, same problem. Thought it was a bad ground on my wiring kit (which is plug and play) and its solidly connected.

At this point, I'm out of ideas. I'm on a 1800-mile road trip from CT to TX, and I'm in Columbus, OH right now with a car I can't drive at night >:(

Is this something I can fix easily (if so please let me know) or will it take several hours for a stealership to diagnose. If I can fix it, I will soon, otherwise when I get to Austin, the car goes in for its 15k service so I'll have it looked at then
 
Back