If you're on a member on 300ZXClub it might be a good idea to contact forum member ZMAXSYSTEMS. He's like a wiring guru on there. I have a full wiring diagram book for our cars at home. If you text me at 3474700828 and remind me later today I will be able to snap some pictures of the wiring diagrams (granted you know how to read them).
Another thing you could do is take it to a reputable electronics shop (place that installs stereo systems, alarms, etc) and see if they could spot the tom foolery).