Hi, Im looking to install a 12 Volt Power Outlet to the port Lazarettte on my 2011 36 C, for a portable fridge freezer [Engel] .On the 301 panel I see the F1 to F5 + VE postive switches, also a -VE negative stud. There is also a second -VE Stud on a terminal trip attached to the hull. What should be the correct connection for the -VE or groung wire?.