You could probably do with getting hold of your particular wiring diagram, it will help you understand just what parts of the circuit are connected to each other to make a complete circuit. There should have been one in your Bailey Welcome pack that was in a blue fabric folder that had instructions on how everything worked in the van.
Failing that, do an online seaech for it, and look for Bailey series 7 wiring diagram for your Ranger model. You don't need to be into electronics in a big way as most of it is pretty self explanitory and the fault you have is a basic one. Remember that you can have no volts if the neutral return wire is faulty or has a bad connection.
Good luck.
Dave.
------------- Never argue with an idiot, they will drag you down to their level and beat you on experience.
Mark Twain.
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