81 kz750 ltd wiring nightmare

I just picked up this 81 kz750 Ltd and the wiring is horrible and I am not good with diagnosing wiring. Can someone help me as far as what needs to be connected. There are splice’s everywhere. Thank you in advance. 

Looks like you have some wire tracing to do. You have a VOM or test light or?  Not sure if this will help as you may have one already, but here is a wiring diag for the KZ750-H2 LTD

The KZ750L3 page below has wiring diagrams.  scroll down and click The Bible link. 
Some of the Ltd diagram years are wrong. 1981 is the H2 and 1982 is the H3. So it should be 81 H2 & 82 H3.

kz.bike-night.com/
 

Oh boy you have your work cut out with this, as an "aside" if you are fixing bikes (or cars) for a living and elec diag isn't your thing you might find my "fault finding guide" useful on the below link
kzrider.com/forum/forum-index/faq-wiki/6...-fault-finding-guide

There are so many things obviously wrong with this bike (not least all the green corrosion which will cause voltage drop issues) at first glace

The White and White/Red joined with a screw cap - this is not a recognised termination method for automotive use and there should be a 20amp fuse between these two wires. This is the main supply to the ign switch so without a fuse any short circuit is a potential fire !!
It looks like the main starter lead is disconnected from the solenoid but in  the first picture the main ground looks like it has been cooked - this may be because the engine ground is bad, if so when the starter was operated the ground wire in the first pic would have gone up in smoke as it's not up to carrying starter current
The yellow/red that is hanging is the supply to the coils from the kill switch

To be honest given the amount of butchering and the level of green corrosion you would be best trying to source another loom that is intact. If you decide to persevere I would strongly connecting your battery with "jumper cables" so you can snatch them off if it starts smoking !!!!!!!

I’ve spent the last hour trying to make sense of this bubba-fied wiring someone did. I’m pretty sure I have it all pretty much figured out. I’m just taking my time trying to sort it out. Here is the freaking positive battery cable that was on it.  

Nice splice 

TexasKZ wrote:

Nice splice 

lol tell me about it. This bike is horribly wired. 
 

If you are going to repair this mess (I had a quick look on ebay and the replacement looms on there don't look great !!) then you need to approach it in a logical and methodical way or you will spend several days going out of your mind "chasing your tail" I would suggest the following before connecting a battery to it

1. Sort the main battery lead to the solenoid - the main lead from the solenoid to the starter - main battery ground to the engine casing
2. Sort battery supply to the fuse box
3. sort the supply from the fuse-box to the ignition switch
4. Sort the generator and regulator/rectifier wiring

Once these steps are complete you have your "foundation" and will have reduced the risk of setting the thing on fire as everything is fused after this point (or should be). From here you can then go through each circuit after the ignition switch and sort the problems as you go along (ignition, lights, instruments etc)

CycleTerminal, VintageConnections & Z1Enterprises have electrical supplies. You should get the correct terminal pins & stuff and a good ratcheting open barrel crimper for doing stock-type crimps.  Terminal pin extractor tools are handy as well (instead of using a paper clip). cycleterminal has a nice set.  I already had a HF crimper but the dies were wrong, so I got a correct set of dies from Aircraft Tool supply. the total cost was the same as getting the correct crimper in the first place. doh. Z1Enterprises has color wire and maybe also VintageConnections.

At CycleTerminal some of the Sumitomo 250 & Hitachi .110 connectors are the same as stock. Be sure to get extra terminal pins for practice or in case you mess up.  At the bottom of the terminal page there are waterproof bullet sets that are pretty nice, handy for fixing that nice splice in the pic. hee.