Adding Fuel Pump Relay and Cut-Off Switch

Hey Folks,

Did some research online but answers vary. Looks like the PO of my Duster installed the electric fuel pump directly off the ignition/fuse box?). Pump runs when key is turned to accessory and run positions. I'd like to be able to disable the fuel pump to allow me to do electrical testing without the fuel pump running. Traced the wires and there does not appear to be a relay? That said, I'd like to add a relay (30 amp?) and cut-off toggle switch. Question, should the switch go before of after the relay, i.e. between fuse box and relay or between relay and fuel pump. Bare with me as wiring in not my forte! :)

Thanks all,
Pat