I wondered for many years why this Green wire was left there, until I met a guy here named Axel, from Japan. He used to have a custom bike-build shop next door to the machine shop I use for my engine work, but he moved to Texas 2 years ago. He was born in Japan and worked on the Honda production lines in 1972-1976, building the Fours and 450 Twins. He was the one who told me about Sochiro riding his 350F right up to the production lines with wrenches in his back pockets, to work on the bikes alongside everyone else. Axel was rotated, like everyone else, to every phase of assembly (except engines, he said that was a special group by themselves), and the electrical phases had test boxes with volt/current meters and lights, and special harnesses to connect to the bikes for checkout. The 'spare' Green ground was universal on the bikes, or a special place for their ground clip identified, and it was the primary attachment point for these testers. The technician had just a couple of minutes to plug his harness adapter into the right colors in the side cover and headlight bucket where the wires were not yet connected together, and then operate all the controls to make sure the switches had not been damaged nor the wires cut (because they ran inside the handlebars and came from another vendor), and the Ground made it to the headlight bracket within a certain resistance, or less.
