I haven't been on for while but looking through your saga here I would be inclined to suspect the dear old 77 connector that is the DC output of the earlier VR.
They definitely can get a carbon buildup from arcing in spread female sockets that effectively insulates one of the pis from connecting to the battery.
The action of reseating the connector can clean this up partially resulting in an intermittent operation.
I had this exact failure on my '06 Uly and after much screwing around with the dealer at the time (still under warranty in the good old days), I eventually found the issue and documented it at the time.
There are all sorts of ways to resolve this but assuming the connector hasn't heated to the point of wrecking the plug I would simply clean the sockets (properly) and reform them as required.
I did that on my Uly and the original connector was still functioning 40,000 miles later when I parked it.
An old version the document I put together at the time is still there in Google docs (page formatting is a bit off but the required info is there):
https://docs.google.com/document/d/1eGkF1pN1dftycPcTD-6Mb4p19gcxWvXEJcIIjEVFycw
The VR has quite a few electronic components so an intermittent internal failure is definitely possible but this check of the connector sockets is relatively easy so can't hurt to try.
Just remember:
1.The 77 connector is connected to the battery via the 30A fuse so is effectively 'hot' with the ignition off so definitely disconnect the battery before attempting this.
2.Take carful note of which of the two black wires from the VR is connected to the red positive lead in the bike loom before removing any sockets (I would suggest doing one at a time to prevent any SNAFUs).
3.The small release tangs do not need to be pushed too far - just enough to release them. If you bend these too far then there is a good chance they will break off when bending them back - not what you want.
Ray
