Just replacing the damaged connector & wiring isn't likely to fix the problem. Something is causing the circuit to draw too much current for the wire gauge size.

So, a voltage drop from the under hood fuel pump power relay to the inertia switch, to the fuel pump, caused by corroded connections & or wiring insulation damage to the fuel pump all the way from the under hood fuel pump power relay to the in cabin inertia switch & from there to the fuel pump belong on your suspect list, as well as a clogged up fuel filter or fuel pump sock/pre-filter, causing the fuel pump to work too hard & draw too much current, also belong on your suspect list.

So maybe after repairing the damaged wiring & connector, begin your trouble shoot by checking for under load voltage drop at the under hood power distribution box fuel pump power relay connections & at the in cabin inertia switch connections, when you go to KOEO & the fuel pump runs for its 2 second prime. If you then still have a voltage drop to the fuel pump at the inertia switch, inspect the wiring & electrical connections from the inertia switch to the fuel pump. If you know the wiring & connections to the fuel pump are ok, suspect a fuel pump problem.

The under hood fuel pump power relay pin/socket connections have been found to sometimes corrode & cause a high resistance that'll cause an under load voltage drop to the fuel pump.
Anywhere a wire lays in contact with something hot, that vibrates, or passes through a bulkhead/firewall, also belong on your suspect list for insulation damage, especially if the wire has been hot from carrying too much current from a circuit overload.

Some trouble shooting thoughts for consideration, keep us posted on your findings.