I believe I answered this yesterday but here it is again.
I tow my 99 TJ behind my 30ft Winny too. I started off with the wiring mess and diodes but thought about it more and came up with something much easier and less expensive. I made a plug in the front bumper and ran my wire up and through the frame to the back with a flat 4 prong plug. I bought the magnetic lights on EBay for $15 or $20 and put the male end of the flat plug on those. When I tow, I just put the lights on the bumper, plug into the plug that hides in the bumper of the jeep and plug the RV into the front bumper. Cost me maybe $30 for the whole set up and a little time of mine to run the wires but a lot less than the $500 some bozo wanted to charge me to do the wiring using the Jeep electrics. This way you do not mess with any of the Jeep wiring.