Ok I bought an autometer tach go's to 10k I believe. Well I have a 94 mustang 3.8l v6 coupe. Well there's the 4 normal wires. Red, white, green, black. Well from the back of the tach there's 2 wires brown and orange. I read on a site that v6 mustangs have to use those wires. . Any ideas where they go? I hooked my red to the battery, black to the fender bolts as a ground, white I didn't hook up and green I went in to the passengers side kicker panel and found the tan wire it a yellow stripe cut it and sauderd. Well the rpms aren't registering. .?!? Is it because of those brown and orange wires? It will let my move the shift light where your suppose to shift at. . Any ideas?????? How do you set it???? Thank you d.mccormick