The way I have it, bypasses the FPC. Im not using the body wiring harness for the power. Im using the relay's power which is fed from the battery. Im also grounding the pumps to the body by a 10ga wire. I feel that is the best method as it is getting direct power by the same gauge wire and it shouldnt have any current drop since the wire size isnt tapering down like it would be if you just tapped into the factory harnes.