Hello Russel,
It is somewhat easy, there is a master disconnect box and a breaker box. You have the wall sockets for plugs and you have the overhead lights. The supply is on the front of the van box and is connected to the back of the breaker box. It was originally a military socket that was plugged in a supply. Many people change it because the matching plug is costly.
The big box to the left of the disconnect and breaker box is a convertor. It converts 115 volts to 24 volts! I removed it from my truck!
NO power underway with the exception of 24 volts supplied to the 2 small overhead lights.
In the disconnect box, there is a built in switch that leaves the 24 volts overhead lights on when the box is on in the off position, when the box is in the on position, only the 115 volt system works and the 24 volt overhead lights do not.
When you are using the overhead 24 volt lights there is a black out switch on the big rear door, it works in conjunction with the b.o. mode switch at the inside rear top right of the van box. Basically you can set it on b.o. mode and the overhead 24 volt lights will turn off when you open the rear doors.
I hope i answered your questions.
http://www.steelsoldiers.com/deuce-...9a3-conversion-progress-setting-standard.html