I screwed up big time....

[jtopiso_imp]

I'd start checking if voltage arrives at the fuel pump with/without the killswitch (or just have someone listen: contact on and kill switch on/off and you can hear the fuelpump working for a second when you swith to "on").

I wouldn't be surprised if there is extra protecction not to allow a melting wire inside the fuel tank, so I'd check that circuit first.

The harness shouldn't be the weakest point on any installation: no matter what you connect it to. Fuses (or some components acting as fuses) are there to prevent wires to get too hot and avoid fires. So I don't think you'll find a melted wire. But I've been wrong before...