You really need to get those brakes working! All those hills in WV
Do you have a brake controller?
I camped up in your area last fall, in a national forest just west of I-77 near Charleston. Way back up in a holler between two mountains, no one around, near some old natural gas wells. Only saw one ranger who collected the fee. I loved it!
That umbilical cord you need may not be easy to find factory made. You can make it yourself, fairly easy. Just go to your local RV or electric supply for plugs and wire. Tractor supply or uhaul may have this too. Get a connector plug to fit each receptacle. The one on the tow vehicle will most likely be different from the one on the trailer. There are flat pin and round pin and a variety of sizes, so make a sketch or take pictures with you when you go get them. Diameter of the plug and pin type is what you will need to know.
A word of caution
: When working on the trailer end, the plug housing on the trailer may be made of magnesium. This can catch on fire if you grind or drill it, yes this metal will burn like a torch. Water will not put out this type of fire. There are threads on this forum regarding this, use the "search" function to find more info.