Hi I’m having trouble understanding which wire is to be soldered to the output jack and which wire to the claw on the bridge. The kit came with the controls and pickups pre wired. There are two black wires and one yellow wire that needs to be connected. Do I need to solder the two black wires to the output jack, if so how do I know which one is the hot wire and which is the ground, as they look the same and connected to the same pot in the electronics. Thanks