I'd do this first, before making up a new harness:
Cleaning Motorcycle Electrics
Get some of the De-Oxit electrical contact cleaner and figure on spending a good day going from the front of the bike to the back. It’s a plastic safe cleaner/preservative.
www.deoxit.com
is their website.
On the older Kawasaki's, a majority of electrical connectors are inside the headlight housing requiring removal of the headlight, then the fun begins.
Do one set of electrical connectors at a time to avoid mixing up what connects to where. Usually disconnecting, spraying with De-Oxit and reconnecting is about all you'll need.
However, when encountering the green crud of corrosion, a brass wire brush may be needed on the pins you can reach.
Some 400-600 grit wet and dry sandpaper strips rolled into a tube should reach the male and female pins in the more difficult to clean connectors.
Smoker’s pipe cleaners, cotton swabs and wooden toothpicks work as cleaning aids.
Really small electrical connectors may require the use of a welders tip cleaning tool assortment.
Most pins in the connectors are coated with a thin plating of tin, and others may be nothing more than copper or brass.
If moisture is added, the resulting corrosion lowers the voltage/current being carried causing dim lights, slow engine cranking, slow turn signal responce and lower input voltage to the ignition coils resulting in weak spark.
The left and right handlebar switch pods will need attention too as they have circuit functions like turn, horn, run/stop, and start.
Usually a spritz or two with actuation of the switch is about all needed for these switches unless corrosion is detected and then careful disassembly is required.
The ignition switch may or may be not sealed to allow spraying the internal contacts. I urge caution if attempting to open this up as springs, and ball bearings may fly out never to be seen again!
If your bike has the older style glass tubed fuses, I suggest replacing them as vibration can cause internal failure. AGX is the type used, and most auto parts stores can get them for you.
Clean the fuse holder clips, looking for signs of overheating(discolored insulation, signs of melting).
I use metal polish on a cotton swab, followed by spraying another clean swab with the De-Oxit and then rubbing the inside of the fuse clip.
All battery cables must be clean and tight for maximum current transfer. Check the cables going from the Negative(-) battery terminal/post to the engine mounting bolt
Also the one going from the Positive(+) terminal to the starter solenoid and from there to the starter motor.
If any battery cable feels ”Crunchy” when flexed, replace it as possible corrosion is inside the insulation.
Each "Bullet Connector" will have to be sprayed to ensure good connectivity, especially the ones going to the energizing coil of the starter solenoid.
The alternator output “Bullet Connectors” are usually behind the engine sprocket cover and will need inspecting and cleaning too.
The turn signal light sockets will benefit from a spritz from the contact cleaner along with the tail light/brake light socket.
Some brake light switches can be sprayed on the actuating rod, with the spray running down inside to the electrical contacts, others may be sealed requiring replacement if the switch is intermittent in operation.
Some people put the Di-Electric Grease on cleaned terminations/connectors, I don’t, as I’ve read/heard it can cause problems when it gets hot, actually insulating the connections, so the choice is yours to use or not.
I think I've covered about all of the electrical systems on the bike.........
“I spent a weekend going through every electrical connection and switch on the bike with a little scotchbrite pad and DeOxit - what a difference! Everything was brighter, gauge backlights, indicator lights, turn signals, I was getting a nicer spark, it fired up quicker, etc. Well worth my time. WELL worth it! “
From a forum member at
www.kzrider.com
Re: Cleaning the many and various Motorcycle electrics.
I used the De-oxit D-5 spray on all the electrical connections of my 78 Kz1000 that had sat for twenty years .
When I parked the bike in 92 I was starting to have troubles with some of the electrical system, but after pulling everything apart and giving it a spray , reconnecting the connectors and working them back and forth a few times, then gave them another shot of spray to wash them off before the final reconnection.
Everything still works perfectly and has for over 7000 miles this year.
I am extremely happy with the results , a lot of the connectors were green when I started and after the cleaning they looked new ( shiny gold )
I found the Deoxit D-series, D-5 spray in a 4 oz can at a big electronics store called Frys in Illinois, don't get the small cans at Radio Shack , they are different and meant for computer type stuff.
store.caig.com/s.nl/sc.2/category.188/.f
Trust MFolks , the guy's a true rocket scientist and really knows what he's talking about.
JD
If there's evidence of extensive damage, you might be forced to build a replacement, the difficulty will be in getting the striped wires in the colors and gauges you need.
I'd use the following gauges for the circuits:
18 gauge, for the turn signals , instrument lights, & brake and tail lights.
16 gauge, for ignition circuits(Ignition coils).
14 gauge, for the headlight circuit.
12 gauge, for the wire going from the rectifier/regulator to the battery.
6 gauge for all heavy duty cables(that's what you call them), from the battery, to high current areas, like the starter solenoid & to the starter motor, and to the engine mounting bolt, for the Negative battery cable.
Welding cable is sold by the foot, so careful measurement is needed before purchasing it. Some welding supply places can also crimp/swage on the terminal ends for you, but if they can't, try a battery supply store, or a place that works on electric golf carts or vehicles.
Topic Author
). I admit, I wouldn't necessarily have thought of methodically working through the whole bike from one end to the other. 
It seems so obvious now!