Hi all. My Elddis Crusader Sirocco 2000 is a great van, but the 12v items only work when the mains hook up is connected. The battery is new-it was fitted by local dealer as part of the 2009 service. I've tried the manufacturers help line but they refuse to diagnose by email saying refer to your local dealer. The handbook supplied with the caravan is generic one covering many models and is worse than useless. I'm certain it must be something simple-a switch or a fuse because everything works fine from the charger once the mains is hooked up. Please help!