2 yellow and black ground wires?

I just removed the battery basket to paint it and in running wires found that one of the ground wires doesnt go to anything. The big one bolts to the block and the yellow and black plugs into something and another yellow and black just sits there- is that for some accessory I don't have or should something be in it? Bike runs fine 83LTD 750twin... and just to tell SOMEONE (wifey doesn't give a ---t (hoot). This is sorta first fix-up to keep it up (other than belt adjust, cable adjust, air filter, oil filter and change and cam chain adjust- ) This was like- clean rust, paint, make some wires nice- felt good!

It can be an extra plug, not used on your model. I have a few as well. Just check over everything you removed to see if you missed something. If you have a wiring diagram for your year/model, it should show up on there.