I would take my tester and check to see if you have power to the plug . Make sure you have a good ground on the tester first and probe each wire to see if your tester light comes on .If there is no power going to the connector I would start tracing back words .If you have power to the 7 point connector and nothing coming out I would say get a new connector or try to take that one apart for a visual inspection . Its kind of strange that nothing is coming out . You have a ground wire ,wired in the 7 prong plug make sure the ground wire is grounded . You can get a color code for that 7 prong plug on the internet just put 7 prong trailer plug in search engine .

 

Should be 2 fuses..

The Body Control Module controls the Reversing Lamp Relays contact closing meaning the internal elect coil, and it’s protected in the Body Control Module F15-15amp. The other fuse is in the Battery Junction Box F43-15amp and it protects the lamp loads through the closed relay. If the fuses check out, and if you have a meter or a test light, relay removed, two of the reversing relay terminals will have power,, one with the ‘Key On’ (reverse selected) is terminal 1 and should then be powered, and the other will be ‘Hot at all times’ on terminal 3.
Terminal 2 is ground (checked to chassis), and terminal 5 is the lamp feed to the 7 way connector when the relay is commanded closed.

Try and verify both applications of power, then check the relay to ground-chassis, and if all prove out, could be a drop out in the circuit on back...

 

 

Basshunter try doing a search for that body control module and see what you find . Maybe do the search and ad you tube ???/ One guy says there is a body control module behind the back seat but didn't specify where behind the back seat. This was from a different forum.

 

BCM is in the R/kick panel and carries fuse F15-25amp, which is ‘key On power’’,, the other fuse F43-15amp is in the Battery Junction Box with the relay.. It should be ‘Hot at all times’.
If for instance a trailer plug/reversing lamps were shorted, or was wired in wrong on the trailer side, F43 would likely pop.. If they prove out, then checking the relay socket/terminals as noted would be the next step..