.......................I'm not sure why all of this should be necessary because all that is really being done is to have the incandescent light bulbs replaced with a much lower wattage LED bulb................
The original wiring uses a "sneak" current arrangement to illuminate the turn signal indicator. the small lamp in the speedo lights up, and, the "other side" turn signal bulbs provide the path to ground.
example:
you turn on the right turn signal.
right turn signal power is applied to the right side of the indicator bulb
current flows through the indicator bulb and into the left turn trafficator bulbs.
(since the indicator lamp is an order of magnatude smaller than the trafficator bulbs it glows brightly while the trafficator bulbs do not reach their illumination point.)
Left turns operate the left side circuitry, and apply power to the left side of the indicator bulb, while the right side lamps provide the ground return.