I am working on the dash assembly of my 74 Barracuda. I have one plug that I can not figure out what it does. The plug has 3 female ports. One has a red wire, one has 2 yellow wires, the other has a yellow with a black tracer wire. There is a tag on this part of the harness that has a part # 3588667 on it. I looked through my 74 service manual and can not find this plug / connector for some reason. Thanks in advance for any help with this, John.