Check the back storage
I don't know if this was the original location, but my wires came out of the bellypan, into the rear storage compartment, then up into the back wall of the trailer. Flip up the aluminum cover of the rear bumper compartment and look to the right (as you face the back of the trailer) They came through a small opening in the frame, on the back wall of the storage compartment.
Like I said, the wires were replaced, so I'm not sure what was original.
Good luck, it's a PITA.