Many issues. Looking for help.

Ok, so I bought a modified bike from a coworker. It's a 1980 kz1000 b4 Ltd according to the zedder website, but has a 1978 kz1000 c1a police motor according to the same source.
From the clymer manual I bought the wiring harness seems to be from the 80.
I've never owned a Kawasaki before, but have an 82 seca 750 that I've worked on a bit, so I do have a bit of knowledge about motorcycles.
What I've run into is when I turn the key on there's no headlight or brake light (it doesn't have any gauges or indicator lights) the blinkers work, so I know the system is getting some sort of power with the key turned on.
Start button does nothing. Kill switch I've turned, and I've looked in the housing. Visually it's not too bad looking inside there but could use a cleaning, which I'll do at some point soon. I spent the afternoon going through it and making sure all the connections were connected and visually checking them for corrosion. They didn't look bad, but again I'll clean them soon as a regular new bike go through.
I put the battery from my seca that's been on a tender for the winter in it (bought it last year). Using a multimeter it reads 12.51 volts across the posts. I cleaned the positive and negative terminals on the bike with a wire brush really well as well as the negative motor ground terminal.
I checked continuity through all 3 fuses, and I'm going to upgrade the fuse box to ATC push in type soon.
I checked for power at the white wires behind the headlight at the 6 pin connector to the ignition switch. Read the same voltage as battery.
I tried to kick it over, but have never had a kick start bike. It turned over, but didn't fire that I could tell. I tried starting it with the clutch held in and not with both the kicker and the start button. Nothing different between the two.
I tried to cross the solenoid with a screwdriver and got sparks but nothing but the light show.
I disconnected the 4 pin headed to the ignitor and checked the pick up coils. Got 4.50 on both so they should be good. They read good at least.

That's the sum up of what I've done today, but I think this bike's got more than a couple things wrong with it and I'm not sure how to figure out much else, so any help would be appreciated.
First thing I'm trying to figure out is why it doesn't even want to try to start. Once I get it to that point I can move on, but I dunno what to try now.

Does the only non stock thing appear to be the different engine or is it more than that?

You said
"I tried to kick it over, but have never had a kick start bike. It turned over, but didn't fire that I could tell. I tried starting it with the clutch held in and not with both the kicker and the start button. Nothing different between the two.
I tried to cross the solenoid with a screwdriver and got sparks but nothing but the light show."

When you said you tried them both and nothing changed it kind of sounds like it turned over with the starter, but then you said you jumped the solenoid and got nothing. Just trying to clarify.

It sounds like you know where to continue at. I would probably start with the starter and/or system (assuming its not working) because I'm sure kicking to troubleshoot is going to get old real quick.

Good luck and happy wrenching!

You stated you bought it from a coworker. Can he tell you how he started it when he used it last? Ed

I should mention that it was running last spring and nothing has been changed on it since it quit running then. When he brought it into the shop the starter was turning but the bike wouldn't fire. They had it for 3 months and didn't really touch it. Told him after the 3 months that it was electrical and they didn't want to dive that far into that old of a bike and sent it home. It was his first bike and he knows little about them so he sold it to me. So he wasn't able to start it and won't be any help 650ed.

The modifications I have seen on it are: the carbs have pods on them, it has a radiator on the front, the handlebars are different I think, it has a Corbin seat, and the blinkers aren't stock. These are the things I think are changed, but there might be stuff I'm missing.
As far as the starter and kicker go I was meaning with the clutch pulled in or left alone the kicker didn't seem to fire at all, but did turn the engine, and the starter button pushed in didn't produce any effect. No matter how the clutch lever was oriented it didn't turn, didn't click, or seem to do anything at all.

Posting some pics of what you are dealing with would help immensely. Hot batteries are big in making anything run, good that you got that. Why would anyone remove the gauges? Oh yeah! to improve it! Because things always run better without any indicator lights and tachometers. lol

Lol, I'm guessing whoever modded it liked the look and wasn't too concerned about lawfulness.
I can produce pictures on demand, as long as I know what y'all want closer photos of, but I'll include a full bike photo in this post.
So, I pulled the starter and applied 12 volts DC across the post. Purred like a kitten, so starter doesn't seem to be my problem.
Pulled the starter solenoid. Applied 12 volts dc to the wires (2 wire solenoid) and it clicked. Read 021 ohms with my multimeter set to 200 ohms across the posts with it energized. Read 039 ohms with it set to 200 ohms across the 2 wires without it energized.
Never checked a solenoid before, but YouTube helped. So it doesn't seem my solenoid is the problem either.
So next is to try testing the igniter and the ignition coils as soon as there's a break in this nasty rain/ snow/ sleet stuff they're calling for most of this week.

Since most of the electrical is interconnected through the ignition switch / gauge cluster inside the headlight, lawfulness wasn't the point. A start solenoid is pretty simple stuff, and is independent of the igniter / ignition with the exception of the kill switch in the right hand control. All are wired through the headlight shell into the main harness. Sorry, I may have missed something in your long intro. It does help to read and make sense, by breaking it up into.. um... relevant paragraphs? lol
Maybe some pics of the wiring you are having trouble with?

BTW, you do not need to pull the starter to put voltage on the main post. You can also trigger a solenoid with a couple of alligator clip jumpers. For ANYTHING electrical to work it MUST have a input and a return. Or as my instructor used to say.. a gozinta and gozouta are both required.

I'd be happy to take photos if I knew where the issue might lie in the starting system, but when I went through checking for corrosion or loose wires they all looked decent on the outside and at the connections.
I'm not the most savvy at electrical work, but I'm learning. I'm guessing if there's an internal break in the wiring the only way to determine where would be to isolate the individual wires and check for continuity, or say ta hell with it and just redo the whole harness.

Camo wrote: I'm not the most savvy at electrical work, but I'm learning. I'm guessing if there's an internal break in the wiring the only way to determine where would be to isolate the individual wires and check for continuity, or say ta hell with it and just redo the whole harness.

That's funny! Not electrically savvy, but going to tackle redoing the entire harness. WHAT could possibly go wrong? lol

Make sure all of the gozinta's and gozouta's are right. A test light and cheap multi-meter will work wonders. No magic bullet on this forum. Perhaps a little research on YOUR part might shed some light on your problem.

Gotcha. I'll continue looking then. I appreciate you're time on this so far.

Camo wrote: ... Applied 12 volts dc to the wires (2 wire solenoid) and it clicked. Read 021 ohms with my multimeter set to 200 ohms across the posts with it energized. Read 039 ohms with it set to 200 ohms across the 2 wires without it energized...

The resistance of the start relay coil when energized vs when de-energized is unimportant.

A starter relay on old Kaws has two sets of two terminals:
The 2 smaller ones energize the electromagnetic coil inside the relay. On a Z1 start relay these terminals have small (~16ga.) wires soldered to them that aren't easily changed. These two smaller terminals are connected to the handlebar start switch circuit. Note that the start relay coil is likely to have very low resistance, on the order of ~3.0 ohms or so. This is important as we shall see shortly.

The two heavy terminals on the start relay are used to supply direct battery power to the starter motor when the start relay coil is energized by pressing the start button. When the relay coil is energized, a pair of heavy contacts inside the relay close, completing the circuit from battery to start motor. One of the 2 heavy terminals are connected to the battery (+) via a heavy cable, the other heavy terminal is connected to the starter via it's heavy cable.

When using a Digital Multimeter (DMM) set to 200 ohms one must first determine the native resistance of the DMM's leads themselves., because most inexpensive DMM's cannot be precisely zero'd.

We don't know the details of your DMM, so we'll safely assume one thing: with the meter set to 200 ohms and the probes not touching the display is likely to read either "1 ." with the decimal a few places to the right or, simply, "OL". This is open circuit i.e. no current can flow. Now, touch the probes together firmly. This is closed circuit; current can flow. Wait a few seconds for the display to stabilize. You're likely to see a reading in the neighborhood of 5.xx ~ 6.xx ohms, although there may be a little drift or "noise" in the digits to the right of the decimal, which can be ignored. This is the native resistance, in ohms, of the meter and it's leads, and can be considered zero ohms for our purposes of testing a start relay and most other things. Make a mental note of this reading.

Now, with the small wires (start sw. circuit) disconnected from from the rest of the bike, place one DMM lead on each small terminal of the start relay. On a Z1 relay I see a reading of 9.xx. Subtracting the native resistance from this reading, we arrive at a start coil resistance of ~3.xx ohms or so, which is what is to be expected.

Testing the start relay for the starter motor circuit itself is only slightly more involved, and a helper might be useful.
Disconnect both heavy cables from where they're attached to the posts on the start relay. With the DMM set to 200 ohms, touch one lead to one of the heavy posts (doesn't matter which) and the other lead to the other heavy post. There should be no significant change in the DMM display (1 .) or" OL". Carefully apply battery power to the two small leads on the start relay. This should energize the relay coil, which closes the heavy internal contacts that apply battery power to the starter motor. If the relay coil is good you'll likely hear a "click. Hearing a click doesn't necessarily mean the heavy contacts have closed electrically, it just means the coil is energized. Now, with the coil remaining energized. touch the leads the DMM leads to the two heavy posts again. If the internal contacts are good, you should see native resistance or very slightly higher on the display, indicating a closed circuit. This is what would be expected with a good start relay. If the resistance is significantly higher, that would indicate burned internal contacts, necessitating replacement of the relay.

A good tutorial on basic DMM use can be found here. Fair warning - browsing the lygte.de site might lead to an addiction to high performance LED flashlights. Don't ask how we know...:
lygte-info.dk/info/DMMComponentTesting%20UK.html

Good Ridin'
slmjim & Z1BEBE

In addition to what slmjim+Z1BEBE, it's a bad idea to connect an ohm meter to an energized circuit like described in the original post. Most decent meters are protected, but in the old days it would do damage. At the very least, it interferes with the way a meter measures resistance so will give faulty reading, and might even give negative results.

Try to measure ohms only when the circuit being tested is de-energized the way slmjim+Z1BEBE described.