I think it'll be a little more complicated than that but thanks for the input. Here's why...
Yellow (Yellow black out of switch) feeds the headlite and speedo lite
Green (Blue/Green out of switch) feeds the brake lite
Grey feeds the tail lite
Grey is the one that puzzles me. There must be a voltage sensor on Yellow (to headlite) in the stator that activates grey (to tail lite) when the headlite is turned on.
So, I'll have to move the Grey feed and connect it in with the headlite switch for this to work.
I think another way is to run two small 6V batteries (which I have :) ) Both are 4.5 amp.
At the connecting block.....
Yellow to + on Battery 1 (with diode of course)
Ground the - of Battery 1 to a brown or chassis
Disconnect grey at block and extend it (the tail lite end) to connect to Yellow/Black either at speedo or headlite
....this will cover the headlite/speedo/tail lite
Drain will be ~36 watts here
Green to + on Battery 2 (diode)
Ground the -
...this will cover the brake lites
Drain is 10 watts when used.
Like I ever do much riding at nite but I'd like to figure this out. Anyone know the exact Voltage/Current outputs on these feeds?