Novastrike wrote:There were two batteries out in series but I have disconnected them all and it’s still doing it. Couldn’t find a split charge either.
I think you mean Parallel !
A second battery added to a camper and intended to power Fridge, TV ,sink water pump etc would in 99.999% of cases be connected in PARALLELL to the starter battery. ie positive to positive (via relay )and both negatives to the vehicle chassis.