Did not go for the day as planned, instead of going by car up and back we decided to take the camper and do an overnighter, but the campers 2 batteries were flat , had started ok a month ago, the ignition switch was off so I had to sort out reason why.
Called out the RAA to start and possibly tell me what was wrong with the electrics , and after jump
start the mechanic said I had short in system , suggested I run engine to charge starting battery and take to auto electrician to check relay that allows 2 battery to retain charge and not leak back to altenator, too complicated for me to understand how it works.
Auto electrician found the relay that was faulty and replaced it also put a fuse in live wire that goes to 3 way fridge and said all fixed, but would probably find 12 volt element that heats the burner part
burnt out and to replace that , the fridge runs on 12 volt when travelling, had an element already and sure enough I had to put it in .