need to know how to install a tach on a 93 teg with 95 gsr motor. i know the black wire is the ground wire, and one of the other wires is suppose to be connect to a 12v source. where can i find a 12v source and what does the other wire connect to. thanks for the help

 

black wire = ground
green wire = tach signal (blue wire behind dash)
white wire = illumination (black/red wire behind dash)
red wire = 12v (black/yellow or black/white wire behind dash)

 

thank you very very much!!!