Hi I need a little help please. Just back from Exmoor 5 days of sunshine, lucky me. On the last morning the earth switch on the site power box tripped and after 30 mins of checking possible problems found that the power would stay on if the last breaker on the van was left off. This switch gave power to the fridge and 12v charger. Can anyone suggest what and to find the problem? The van is a 2003 Swift Challenger 500.Many thanks Andy