ECU/Fuel pump issue?
 

ok so this might be long and I apologies ahead of time but its a complicated story and question.
My g35's wiring ended up just getting absolutely tore up by previous owner trying to install an autostart, he spliced into, a lot of different wires from dash harness and fuel pump harness. I'm very bad with wiring but I purchased a dash harness and got it all bad to om spec. however the fuel pump still wont kick on, I know the fuel pump works because I had tried to install a power switch from battery to pump and it cycled perfectly but it still did not fire. I'm not sure if the ecu is not picking up that the fuel pump is being turned on and not sparking or if that's even a thing. I'd rather not dump money into getting another wiring harness if I don't have to. I have tried searching to see if anyone has installed a switch for fuel pump but came up with nothing. If there is a way to wire in an external switch for my fuel pump can someone point me in the right direction as to how as reference to see if I did it right, thanks.
Thank you for your time I hope that it wasn't too confusing.

Sounds like NATS / IMMU (security) is interlocking your fuel pump.