Busy swapping caravan, and car, from 7pin 12N and 12S electrics (older dual plugs, and cables), both over to 13pin single plug socket. I made a point of ordering a kit able to accept twin cables, but the kit was made for one thick and one thinner cable - both of my multi-core cables are thick versions - making it very difficult to fit cables, in the water-proof sleeves..
Managed to complete that yesterday, but fowled up big time...
I tested it when it was becoming dark, and got some strange results, and half lit lamps, so I abandoned it for the day. This morning, I began checking the socket and found there was no power there at all, so I began ripping the all the boot lining out, glove box, to trace the main feed, and why it lacked power.
After several hours, it finally dawned on me, I had fitted an ignition powered relay in the main feed, to avoid the fridge/secondary battery, voltage controlled switch, discharging the car battery. It uses a fancy BMW system, to check confirm the trailer lighting, is all working.
Having got the power on, it was still not right, I had wired the plug following the connection diagram, but the diagram viewed the pins from the pin side, rather than the terminal side. Once corrected, everything worked just fine..