Rear running lights not working 2007 yaris

[spectra]

All of my rear running lights stopped working.

About 2 months ago I had u-haul add a hitch and wiring for lights.

I have not even been back there to see when they stopped this whole time but I noticed last night that all lights work other than the red running lights that should be on at night.

U-haul says its not there problem because it has been to long.

Which wires should I look at, I checked all fuses in the fuse box and there were no dead ones.

I really think it has to do with the shitty wiriing job by uhaul.