RV Repair: 12 volt wiring, tent trailer, initial check

Question
i have a 1983 coleman colonial tent trailer my 110 wiring works but not the 12volt my dealer in the area says he cant get a wiring diagram for me because trailers too old would you know where i might find one or how i might trace wires they disapear inside frame

Answer
Bill, Unfortunately the dealer is right and they just don't keep wiring diagrams for the older ones. I would first make sure that the converter is working. It should be near the breakers. Then I also believe that you should have a battery/ converter switch. If so make sure that when you switch it there is continuity to the right posts there too. It is very unlikely that all the 12 volt wiring went at the same time. Check for power at the 12 volt fuses and either go back or forward from there after the initial check. Thanks, Bill