the boxed numbers do take a leap of faith..
but trust me and take out the haynes and turn to
wiring diagrams 12-23
There you'll see your coil marked
N
from the coil is a wire marked sw.. that ends at
[20]
look at the bottom of the page, there you'll see a line with numbers.
follow the numbers till you get to 20 (page 12-26)
there you'll see a wire attached to this number and a number 15 in a circle
this circled number is an earth point that both wires use. It's location is told in the legend of earth points
Another example on page 12-23 is again from the coil (N)
there you can see the boxed number
[24]
again look at the line below and follow it to the number 24
you'll see this is connected to the choke air bypass cut off valve or
N3
then continues on to another boxed number
[12]
simply follow the bottom line back to number 12
you'll see it is located at the plugs or engine block
so it's a circuit that energises when the ignition is on