Let's find out if you bike's wire harness is ok.
Disconnect the battery.
Do a continuity check (measure resistance), between the disconnected green at your alternator and the battery NEG terminal.
Repeat the test with the disconnected green at the reg/rect and the battery NEG terminal.
Is a basic theory of operation of any interest?
Ran a couple of recommended tests this time and here's what I did and what I found:
For the rectifier test, I took it out of the bike completely, put it on the work bench, just me, the device and my multimeter.
I set my multimeter to Ohms 20M.
Ground in the rectifier against the ground (black) in the multimeter:
Yellow 1: 3.82
Yellow 2: 3.48
Yellow 3: 3.59
Ground in the rectifier against positive lead in the multimeter:
Yellow 1: No reading (Infinite?)
Yellow 2: No reading (Infinite?)
Yellow 3: No reading (Infinite?)
Red in the rectifier against negative lead in multimeter:
Yellow 1: 3.85
Yellow 2: 3.47
Yellow 3: 3.62
Red in the rectifier against positive lead in multimeter:
Yellow 1: No reading (Infinite?)
Yellow 2: No reading (Infinite?)
Yellow 3: No reading (Infinite?)
Is this good?
I also ran your other test for resistance in the wiring harness. I unhooked both battery terminals. I placed the negative lead against the battery negative. I then place the red lead against the green wire at the alternator connector block (the one coming out of the case). It read nothing (infinite?). I switch the leads around, still nothing.
I did the same with the disconnected greens at the rectifier/regulator, same results...nothing on the meter.