Hey guys got an 87gn and just bought an autometer tach, i know the red is your power and the black is your ground, i also know to snip the brown wire for our 6 cylinder cars but where does the green wire and white wire go to thanks
White wire - connect to the terminal on the fuse block labeled "LPS" or "lights". The white just operates the internal lighting in the tach for at night.
The green wire - pop the hood, look behind the alternator/air conditioner compressor area. You should see a grey wire with a single green plug with a male terminal inside. Connect the green wire here. The green is the sensing wire that gets the reading off the coil.