3023 Marker/running lights out in rear section only

Last trip out the marker lights were out, only in the rear half of the trailer.

Donnie at TM sent me to the connections between front & rear- thought it would be the green wire corroded.

Opening the connector between front & rear on the green wire does show +12V, so I think I'm looking for either a break in the green wire downstream, or a break in the return that I don't yet know about.

All other lights work OK, so I am assuming the return/ground (white wire) is good at the connection between front & rear.

I'll try Donnie again, but wanted to know if anyone else has already found & fixed this problem.

Dan