This was written and put together by Wes White of Four Aces Cycle in Pacoima, California. It was posted here with his permission, it is a great look at how to give your bike a really nice wiring job with cloth covered wire.
To me nothing ruins a flashy period custom or a bike (that you just want to be nice and tidy) like that plastic covered wire and those ugly crimp connectors that get all misshapen and crunched when you crimp them. How about just a bike that has a big snarl of wire masquerading as an electrical system?
So here is one solution… It takes a lot of extra time comparatively but the result is undeniably better. Go and get yourself some black shrink wrap in a couple of different sizes and those boring crimp connectors. Then get some nice cloth covered wiring for your motorcycle. Typically 16 gauge wire works for your general wiring such as lighting while 12 gauge cloth covered wire works when you need something that can handle a bit more load.
First thing you need to do is strip the plastic off of all of the crimp connectors. This is tedious and boring and sometimes painful depending on whether you use the dykes or a razor blade. Here in the San Fernando Valley we have a couple of old time electrical shops that sell connectors that do not have the ugly modern plastic dealies around the base, but some of the butt connectors are not available. If you cannot find an old shop, just start taking the plastic off. This gives you a nice clean connector. (note: quick and easy way to remove the plastic, just heat it up with a lighter and pull it off with with a pair of needlenose pliers)
Strip your wire carefully then slip a little shrink wrap around the wire. DO THIS FIRST, otherwise you might not get it over the connector. Then add the connector of your choice and crimp CAREFULLY. Slide the shrink wrap over the connector and fire up your Bic lighter and shrink the wrap on the connector. Nice and clean. When you are using butt connectors, you can slip some bigger shrink wrap around a couple of connections to make it even cleaner. Look how much cleaner things are when you use a little extra shrink wrap on the wires coming out of the regulator. With some planning you can also use asphalt wire loom to keep runs of several wires nice and tidy, as well as protected from sharp edges they may encounter, and the elements.
You can even get crazy and run little curly wires to various parts of your electrical system. I would not get carried away with the curlies though. Too much of a good thing can be bad. A couple of discreet ones look good, your whole bike in curlies is kinda weird. Just take a screwdriver and wrap the wire around it in a tight little roll. Remove screwdriver and you have a nice, tidy curly.
Oh, and if your hands are always dirty like mine, wash them before wiring your bike, the light colored cloth wire can get dirty fast when you handle it.
So if you don’t like your wiring, spend $40 bucks and get after it. If you have already wired your bike or had someone else do it for you, you can just replace the wires with cloth covered wire or replace the connectors only. This will also teach you a lot about how your electrical system works. Using some cloth covered spark plug wires will match your new, tidy wiring and add that vintage aesthetic.