@ Turtlehead - I unplugged 4 pin connector and started the car. Let it run for maybe 1.5-2 minutes and the alternator did not "kick in" as the volts read at the back stud were same as battery voltage.

Followed the steps on 4-27 of the service manual supplement.
1 - yes
2 - yes
3 - no
(4-5 - turn off ignition, unplug 4 pin connector)
6 - does batt light turn on when turn ignition on - No, go to step 10
10 - measure volt at black/yellow wire in 4 pin plug. If batt volt (it was), replace alternator.

WTH ! At this point, remember the original alternator "tested good" at 2 different Advance Auto stores off the car, just to make sure one wasn't BSing me

Skipping the regulator tests since they'd be part of alternator and shooting down to 4-30, continuation of the troubleshooting:
Test 4 - start engine, turn on high beams, is there 1v or less on wht/green, yes, had like .04 or .08, go to step 8
(8 - turn off headlight and ignition)
9 - Disconnect PCM connector C (31P) - edit, found this under middle of dash, pulled blue plug.
10 - Check for continuity between PCM connector terminal C2 and alternator 4P connector terminal 2 (white/green). If continuity, test alternator. If not, repair open in wire between alternator and PCM.

Using a Klein DMM, it was showing no resistance, so from what I understand thats OK (open circuit would be max). I stripped a piece of wire and stuck it into the 4 pin plug, ran the end of that wire the 6 ft or so into the passenger side floorboard where I connected it to the DMM probe, and the other side I stuck into C2 terminal.

So all points back to the alternator... Possible I had a bad one off the shelf but doesn't explain why the original one still tests OK. Unless anyone has another suggestion I'm going to get another alternator and "restart" there...

 

Mystery solved! Well, sort of...

Last night took a deep breath and installed another rebuilt alternator (from Autozone), after having them test it before I left the store. With fully charged battery, fired it up and all was well!!! Cleaned up the battery terminals nice and hit them with a shot of protectant for good measure.

I think I'll probably spend the $30 on a new ground cable for piece of mind as probably 25-30% of the strands appear to be disconnected, but for now I want to leave for a few days (it doesn't get driven often anymore as I have an electric Honda Fit) to see if for some reason the lights come back on and I have issues again.

I haven't yet had the 1st rebuilt alternator tested, but am curious to know the result. As a reminder the stock alternator, which was installed when the problem first presented, did "pass the test" per two different Advance Auto Stores, which is all done by a computer system now, not like 10 years ago when they read a gauge.

 

A few things. First I am glad to hear it is working at this point in time. Secondly I would not trust the bench test they perform, it is best done on the car with the car under full electrical load. Third they do not have the best rebuilds on the market so keep that in mind. In the future you can look for a parts place that carries Denso rebuilds. Denso made you original alternator and have been the rebuild source for Honda for many years. They are harder to track down as an aftermarket but worth the time and added expense, but they are still cheaper then the dealer with all the mark-ups. Keep us posted on how it works out over the next week or so.

 

I worked at Autozone a little more than 10 years ago while in college, and had bought one then to replace the OEM one because it died. Like I said, I've had the car a while Since they have the lifetime warranty and it lasted that long, I figured since it was free and not that long to swap out, it was worth it.

I have seen plenty of early failures including DOA in my time there, same at Advance Auto. Whenever I bought parts there like that or a starter, I'd test it myself before leaving. I do a lot of work with snowplows now, and it is mind boggling the out of the box failure rates for Napa and similar store starter solenoids... I'll sell wiring to someone for a self-install and they'll replace the used solenoid thinking they are doing something good to avoid future issues and then they call when it doesn't work. For similar reasons, for most electronics or electric motors (think window motors, wiper motors) etc I recommend Denso or the OEM version (Motorcraft, AC Delco) etc because most of the 'regular' aftermarket stuff is garbage.

 

Always remember, all stores have a habit of changing vendors for part manufacturing and for rebuilds for bottom line costs.