Missing wire

[rbr]

Hi, all
While converting to LED running lights on our new-to-us 2004 Safari 28, I found that the backup light black wire is "missing", and the backup light is wired into the stop lights. The PO did disclose that he had bought the trailer wrecked - rear ended w. damage to storage box and lower rear quarter panels only. He had this repaired by a dealer to the tune of 6K+ and is cosmetically excellent, but it appears the wiring was screwed up. My question is: Where are the wiring harness connections for the rear indicator lights, above the storage box under the bed, below it in the belly pan, or in the wall? Not having a backup light is not a critical safety issue, but I want to make it right eventually, and at some point may become obligated to get a state inspection. Thanks,
Bruce