So the instructions seem to indicate that I should have 2, maybe 3 wires per pickup. I have 4. One is white and 3 are black. I am assuming the black are some type of common or ground as they were all soldered together and to the bottom of the bridge pickup pot.. The bass is a MIJ '75 Fender Jazz RI.. seems to have fairly standard single coil pickups.. i don't know what the deal is. Where do I put all these wires?