Just cuz your car wasnt a auto, doesnt mean its not going to have stuff on the wiring harness for a auto. They make the same wiring harness with plugs for tachs, auto stuff, ac, wither or not your car came with it. You think there going to produce a different harness for each car? Its for the auto shifter that does the lockout and lights to light up the shifer, and overdrive functions. My car has it as well. I cut it and used it for a power source when the lights are on for my glow gauges i put in when i was a ricer fool. I love how the white gauges look, but i unhooked the ballast when i got the car back lol, no longer in my taste.