as most of you know I am converting an ambulance to a motorhome by useing the inside of an old caravan, well just about finished now but the water heater just won't play right, if the engine is running it works without fault , same if on hook up , but just on battery it comes up with the low voltage light and won't work , but this is a new batteryand always shows well over 12 volts , I have rung the expert in Nottingham that always comes up on searchs but he doesn't understand it , is there something somewhere that reads the voltage or what, it's not supposed to cut out till it drops to 10.5volts but it's nowhere near that low.
What can I trynext?
What can I trynext?