so does that mean the relay is switching on the power side? I'm just trying to figure out what you meant. I know how they work, I just want to make sure I understood you correctly. Maybe I'm just not thinking straight right now.
switched power to the relay coil, and to ground. Heavy gauge wire (on a fused circuit) from the battery to the switched side of the relay. The other side of the relay goes to the pump positive, and the pump ground is a heavy gauge wire just straight to ground?