What color is the wire for the fuel pump to turn on

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. So sorry to hear you're having trouble with your vehicle. The fuel pump wires on your Mariner should be red(ground) and white(power), but this can vary depending on the specific trim or setup. Since you've spliced the harness and now have issues with the fuel pump and starting, it sounds like the fuel pump might not be receiving power or ground. When inspecting the harness, I would pay especially close attention to the splice points. I would also recommend confirming the inertia fuel shut-off switch is in the correct position. It should be in the passenger kick panel. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!