When I field tested mine, I hooked 12 volts from the battery to the female terminal at the relay that feeds the fuel pump. It will either run, or it won't, it doesn't need power very long to determine if the problem is with the pump or not. Doing this eliminates everything between the battery and the pump except the immediate wire to the pump, the pump itself, and the pump ground wire. Once you determine which wire powers the pump, you can also power the pump right at the pump if need be, but you would also probably have to provide a ground for the pump as well.
If the pump runs when 12 volts is applied in place of the relay, then the issue is before the relay, probably the wire splice discussed before. Gene