Alternator help

However, because the wire itself is loose, I need to replace it. But the replacement connectors out there for the 4th gen LS1 F-body seems to come in 4 wires:

How can I go about making the switch? The single wire is spliced with another wire, so I'm not sure where the rest of the 3 wires are supposed to be spliced with. My vehicle does have an aftermarket stereo system installed, but I'm hesitant to believe that it exclusively depends on the single wire output...
Where can I get a replacement connector harness that has only one wire?





