If you could take the pictures from a bit farther away it would help to get an idea of what we're looking at.
On the second picture that looks like it's the wiring that would normally go to the mechanical voltage regulator. It's a common upgrade to change to the 280ZX internally regulated alternator, when you do that you need to bypass the old voltage regulator by jumping the two wires that are taped off. I've done that on my car and it's great. There should be a pretty big black box type thing on the passenger side between the strut tower and the battery area, if that's removed then you know you've got the ZX alternator mod.
Edited by KevvinG, 09 April 2017 - 01:23 PM.