Please can anyone help with wiring for a Spectrum SPB221 Bass?

First, I just want to say that I'm SO grateful that this forum exists! I would otherwise have no resource at all to attempt to repair my beloved bass. It is a Spectrum II, model SPB221 BK. Neck plate says 88 01 0218, it may be one of the last models off the Matsumoko line, at least I believe it is. Well... the issue is that the neck pickup (a Magnabass II) is not responding. I do have a disconnected wire showing in the back of the bass, and I am not sure where it would go. I was unable to find a wiring diagram on this site that matched what I'm seeing inside my bass. I suppose I would also need a way to test the pickup directly. Please, if anyone can provide a wiring diagram, or perhaps suggest troubleshooting steps I would be very thankful. I am not great with electronics but I can follow a diagram and do basic testing.  
Thanks in advance to any who may reply!

Hi buzzy and welcome to the nut house. I'm not a bass guy but I'm sure someone who's more knowledgeable will be along soon.

Meantime, I can tell you that your bass is not Mats built. It's Korean, 1988.

Have a look HERE for a description (scroll down), and HERE for a wiring schematic which may help.

Thank you Barry. I was hoping it was a Mats bass because of it's early 88 build and being a 22 fret model. But, hopefully it will be better news from here on out!    I did see the wiring link that you provided (thanks), but it is confusing to me a bit because of the active components and battery, which my bass does not have.