I'm just in the process of buying a new van conversion based on an 07 reg [new shape] citroen relay. All the 12 volt appliances, compressor fridge, water pump, lights, etc, have been earthed to the vehicles chassis and not directly back to the battery. I've been told that by doing this it could disrupt the engine management system and it's only ok to earth to the chassis on older vehicles as their ems isn't as complicated or sensative. Does anyone know if this is true or not, as i can't find anything relating to this on the net, and if i do buy it i don't want to go to the trouble of rewiring the appliances.