Two-wire mod report
Well, at least I didn't violate the first rule of doctorin'/mechanicin': do no harm.
At best, I might have eliminated a slight parasitic loss of some kind in the JB, but it's difficult to tell... Normally, when the weather is as hot as it is right now, seeing a charging voltage in excess of 13.1V on this bike is a rare event. I'm seeing 13.1V at *idle* now (dropping to 12.6V if I turn on the directional signal), and at anything over 1,200 RPM or so, 13.1V is the new minimum: 13.2V being seen often, and occasionally 13.3V. Charging system doesn't seem to be working as hard to stay above 13V, but that's about all the improvement I note presently.
As far as the work itself, I won't rehash most of what's already in several good threads on this mod. If you don't have a copy of the service manual from TOC, get it. Page 15-30 has a diagram of the electric starter circuit that should confirm for you that pins 11 and 13 on the 10-pin connector are the wires of interest. What the diagram *won't* tell you is the physical location of those pins. The pin-numbering scheme for the JB connectors is definitely NOT what I'd call sensible. Page 15-50 of the service manual has a diagram of the JB connectors with the pins numbered. Here's what I mean by "not sensibly numbered":
With the JB in its usual orientation, the outside five pins of the 10-pin connector from bottom to top are 11, 12, 13, 5, and 4. The inside five pins from bottom to top are 15, 9, NC, 14, and 16. You care about finding pins 11 and 13, which are associated with the JB's starter relay identified as component number 27 on the diagram.
The service manual says the wire in pin 11 is black. Mine was black w/red stripe as reported in other two-wire mod threads. The theory is early model year bikes do, in fact, have a black wire in the pin 11 position. The pin 13 wire was yellow w/red stripe in agreement with the diagram.
As I had previously accomplished the blue-wire mod, doing the two-wire mod didn't affect the functionality of the existing headlight circuit.