All good. Thought i might be able to save the diagram & load it up here but best you hit download [ok you have] i'm having trouble saving it as a big pic.

Just printed it out, that's going to be a big help, thank you!

Maybe just an aftermarket plug to connect a battery charger, while in winter storage?
But then, 2 wires are enough

The mystery plug for sure plugs to the Yamaha CDI.

Thanks guys, got it all connected and have spark only problem is that's it, no light or horn weird thing is I thought maybe ground so I connected my test light to the negative side of the battery and touched the probe side to ground and it lit up, what's up with that! 

Front or back light, Tony?

Front might only work with engine running? Horn could be a slightly corroded button, or the points on the inside of it need cleaning. Have you connected it direct to the battery and have you circuit tested the pink and brown wires, with the horn button pushed? Switchgear earth to the handlebars is ok? 

Good morning Alan, no lights at all or signals. I have a new rebuilt left side switch (restored by Deet). The thing that's bothering me and makes me think I've got something somewhere wrong is connected test light to negative side of battery then touching probe to a bolt head and it lights up. Have I ever mentioned I hate wiring!

Had a battery at work once [or a bike that came in with it already fitted [12volt] that had been charged up back to front.
I think it was fitted connected correctly in the bike Was 50 years ago but i'm sure i recall flattening it 'more than flat' then charging correctly & was ok.
Would have been a generator system [not alternator] like on an early 125 YA6 or similar as with generator systems the battery can go in connected back to front & works [won't blow a fuse] but won't charge. Well think it will charge if the cutout is momentarily held closed to reverse polarity of the system.
Maybe i'm talking rubbish [enlighten me--was long ago].
I guess none of it is relevant to this post--but started off thinking it might be.

Thanks Morley, this is the battery I had in it before I tore the bike down. I did have to put it on the trickle charger but it must of still had some descent charge on it as it only took a short time to charge. I did check the voltage on battery, it's showing 12.59 volts.

No quite sure i'm understanding right. But if you touched the probe to the battery negative terminal [on the battery] then go direct to ground & it glows--is the negative battery lead broken within.
I'm pretty basic on electrics but thinking if the probe lights up then the positive side of the battery must be going somewhere [through a bulb or something & to ground to get a complete circuit through the battery.
Or are these probe things just super sensitive & show power is hiding in the wire even when nothing is turned on.