[kipps]

Look for a year-correct wiring diagram among Hatzie's collection(see his signature). Identify what you can using wire color and approximate size. Then confirm your ID by checking ohms between both ends of the wire.

For example, you'd look for a wire that matches one of those unknown pigtails. When you have a likely suspect, you check for continuity between that pigtail and the supposed other end of the wire. If you have continuity, you've successfully identified that wire.

A last ditch effort that is still surprisingly effective, is connect an ohm-meter to that unknown pigtail, and then while all other connectors are disconnected, just start probing all of them at random. You will get a hit at some point, confirming both ends of a circuit. When dealing with the fuse box, you'd want to do this with the fuses out, since they can really confuse things.