Ok my Maplins split charge relay arrived today I still need to get some wire,connecters and an 8amp fuse to ncharge my 85amp hour battery. Looking at the diagram am I right in thinking that both batteries are earthed from the negative terminals likewise the unit is also earthed and that there is only one feed into the unit which is fused from the alternator? Think someone scanned a picture up of this unit somewhere. Unfortunately electronics is not my chosen occupation.