Hi all. New member here.
I'm replacing some pickups in my semi-hollow guitar, and a bit confused about the wiring requirements.

This is not a kit guitar.

Pickups are Artist Bullbuckers. Instructions say to solder white and red together, which I've done. Yellow is hot, black ground.

But what is the extra black wire for? It's been taped off so I assume I don't need to worry about it, but the Artist info doesn't really explain what it is.

I have a pic but not sure I can post it yet.