m&h backup light harness

I am doing a 4 speed conversion in my 72 dart and I ordered the m&h backup harness. I have the wiring figured out for the rear and dash mounted lights but there are still 4 wires that I can not see what they are supposed to connect to, 2 are under the hood and the other 2 are underneath down by the trans. Has anyone used this harness and are the other wires necessary. I will try to post some pics of the wires I am questioning tomorrow.