my first question to you is, are you going to gut your trailer, and if so are you going to put it back together in its original design, if you go back to an original design then a schematic would probably be helpful but if not a good understanding each of the different systems would be the most important thing.
brake, running and reverse lights and electric brakes which are controlled or powered by your tow vehicle
110 volt system, possible needs ac unit, water heater, refrigerator, hair dryer a must for the wife and any other appliance you might want to plug in.
systems, possible needs vent fans, lighting, ignitors for propane water heater, multi power refrigerator, radio, tv, sensors and ect. ect....
now that the basics are understood now its time to understand the limitations of each system and know how each system works.
I'm in the process of gutting my 02' as international and yesterday removed 90% of the electrical wiring and carefully tracted each wiring especiallaly sensor wires and brake and running lights wiring, for the rest of the wiring I'm not concerned about since I'm going to install a custom interior, with the understanding of the limitations of the univolt system my trailer has.
the univolt system has three basic functions it manages your 110 volt system, 12 volt
system and also charges your battery when plugged into shore power.
did I forget to mention I'm an electrician.
if you have any question feel free to call me @ 650-270-7632 between 5pm & 9pm pacific time I don't do well on the computer.