[pcdodson]

I hooked up a tach which connected to three wires coming out of the control box. There are three more wires that are unused. They are pink, yellow, and black. What do these wires operate? Or where can I find information on this. Thanks in advance

[rodbolt]

I think you hooked up the wrong wires
out of the 703 box the light green,light blue and red are trim control wires,black is gauge ground,red is 12v, yellow is key on 12v and dark green is tach send.