Wiring question

[fuelpump]

I'm putting a tach in my 60 and I'm siting here looking at a wiring diagram in the shop manual trying to figure out which wire (coming out of the light switch) I need to tap into to get the light in the tach to turn on when I turn on the headlights. If I'm reading the wiring diagram right (fat chance of that!) I can tap into the light green wire and have a light in the tach when I turn on the headlights. Am I correct? Or is there another wire I should tap into? Thanks.