85jeeper

hey guys. i've got a 5.3 vortec from a 2004 chevy avalanche in my old jeep, and i'm having problems w/ the tach. the pcm was reflashed to have the autotheft and other various things removed from the system, and as a result, the #10 pin on the pcm block no longer puts out a signal for a tach. i was told to purchase an automter tach adapter for my autometer phantom tach. it seems pretty straight forward: black wire to ground, red wire to 12v ignition switch, gray wire to the tach, and red/green wire to a coil postitive(12volt) supply wire. i'm having the worst time trying to figure out which wire on the coil to tap into. the pink wire is hot when you turn the key on, but it goes into the same ignition that the red wire was tapped into. where the heck does the red/green wire go !? thanks for the help!