Ugh. Alternator...
 

So the alternator isn't charging on my 90 5.0 Miata. I had the alt teated and it passed 3 tests.
All connections are good and as follows. Two black/org thick wires from alternator to thick Miata white wire which runs to fuse box under hood. The wires are constant 12v. The white and black smaller wire is tapped to the white/black of the other alt side connector. The yel/white alt wire is connected to the Miata white/grn wire. The grn/org alt wire connected to grn/red Miata wire. My volt guage is a brand new guage.

The yellow/white wire also has 12v.