The 7 pin connector connector in the picture is 100% aftermarket; if it was OEM, it would have Henry's surname molded into it.
I have a number of the EVTM (electrical, vacuum troubleshooting manual) and Ford never ran more than 4 wires to the rear of Ranger for trailer wiring.
Now, the good Ford trailer hitch comes with a steel clip that the 4 pin flat connector slides into. But it wasn't made of any too thick steel, finish wasn't best (just cheap paint, no anti corrosion treatment) and location is bad for rust.
My "cheat" was to grab the 7 pin connector and wiring from an F-150 and splice into Ranger wiring appropriately. But I was only looking for power for my camper, as my trailer has surge brakes.