not fuel pump, but wiring?

[dbestnindy]

I posted about a fuel pump but after further checking it in not the pump. The wire that plugs into the pump is dead. Tje wire for the gauge is working (same plug) but not the hot. I am a female so cut me some slack please. Does anyone know if I can just replace this wire instead of the whole harnass and to where does the wire end up?
Thanks,
Debbie

[Jeremy-WI]

The wire for the pump will only have 12v when;
1) the ignition switch is turned on, it will have power for about 2 seconds.
2) the engine is cranking over or running
3) the oil pressure sending unit detects approxiamately 4 psi oil pressure
4) 12v jumper is installed on fuel pump prime connector.

The wire that feeds the pump 12v usually ends up at the fuel pump relay and is spliced for the oil pressure sending unit