Wiring aftermarket guage

Need help please. My z500b3 81 needs a new guage with indicator lights for High beam, turnsign, back light and neutral. Ive managed to get all indicators to work properly but not the neutral. Ive tried many combinations but not the wright one....

Anyone that can save me from madness;)

Providing wiring diagram and picture of new guage leads.

The wire going to the sending unit (switch) completes the ground.
Steve

Thanks. Yes the skyblue lead goes to the switch. So i Connect the black ground on the new guage there? But the green lead on the new guage goes to the brown in the old Wiring?

Try connecting the brown wire to green & black-2 to light green from the neutral switch.
Brown is a power wire. I'm thinking the green neutral gear wire is the power wire for the N indicator light & of course black-2 is ground.

As swest says, you need to complete the neutral switch circuit to ground. In the wiring diagram there is a light green wire from the neutral switch to the indicator-light at the pilot box, so you probably need to connect black-2 to light green.

edit: originally thought neutral switch wire was grey. doh. see loudhvx reply.

Swedez500 wrote: Thanks. Yes the skyblue lead goes to the switch. So i Connect the black ground on the new guage there? But the green lead on the new guage goes to the brown in the old Wiring?

On the bike, the wire to the neutral switch is light green (not sky blue). That switch is the ground for the neutral light.
(The sky blue wire in that area might be the oil pressure switch wire, but it should have a red tracer on it.)
Your gauge should get power from the bike's brown wire. I think this goes to the green wire on your gauge.
Your gauge will provide that power to the bulb internally (through the green wire).
The ground side of the bulb should have a wire coming out of the gauge. That looks to be that second black wire you have labeled Black-2. That gets connected to the light green wire on the bike's harness.

Your diagram is not posting at full size. Here is a closeup from the original scan.

This must be it. Great. Do you have a high resolution diagram to share?

Best of wishes

Kz rider tends to reduce the size when you post it, so you might already have the full-size version.
These are the original size scans (there are several diagrams posted there):
s3.amazonaws.com/gpzweb/Mnls/Kz400500550...z400500550wires.html

Yours are better than mine:)

If you follow the links in my signature, you can download several different service manuals, and there is a website for your carbs that you might be interested in.