Electric fuel pump

[waltraud]

I'm going to add a 1.5 to 4psi posiflow pump for my dg to assist changeover from lpg. See diagram that im using for pump relay. I need a switch in the system, would it make most sense and be safestto wire the dash switch to break the earth or live cicuit? It needs a switch as running lpg mostly and i dont want to wire it directly to the lpg switching ni incase it dies. Thanks for an hints

[waltraud]

Any electrical fetishizts or gurus available?