Proper way to connect fuse box

Hey everyone, first post here.

I bought a used 2008 wr a few weeks ago. While adding farkles today, I noticed something strange with the fuse box. There's a red wire running into the fuse box and a black connected to a ground point. The black/red I just mentioned are on one end.

Then, the other end with black/red is connected to... nothing. It's been clipped, just hanging there!

I suppose the red on the clipped end should go straight to positive on the battery. But does the black go to negative on battery? Does it make sense to connect the black to neg since the other end is connected directly to a grounding point?

Thanks for helping solve the mystery!
Jeff

Not sure if this helps, but here are a couple pics I found online.