Westone Thunder IA Bass Guitar Wiring

Thank you Barry for that link. That's one of the ones i found earlier with the 2 pickups and the colours are different. Is their dual tone the same as the bit on the back of my pull/push rotary knob? I suppose if I stop and think about it the three cores from my pickup land on non-ground terminals so I guess by a process of elimination the 4th must be ground. I guess it doesn't matter which bit of the ground linking it solders to. Am I barking up the right tree? The pink highlight is the push/pull/turn knob with the plastic wheel missing. The left most knob in this picture is the one with the centre detent. It's a while since this one was last used and I can't exactly remember which knob does what.  

Thanks for helping me to think it through.
Cheers

Don't know enough about these beasts. Damian, anything?

I'm not too sure either; on my passive Spectrum LX Bass, the bottom tone pot push/pull is phase reverse, and that's the only push/pull it has. 

I'm pretty sure the controls on yours will be volume, tone and pre-amp volume, top to bottom. Is the mini switch the pre-amp on/off?

Connect the loose black to your pink arrowed terminal.

Controls are volume pull/push series/parallel, passive tone, active tone. Mini switch active on/off.

Thanks everyone for your help. 
I'm not even sure that the active bit was working/had batteries last time it played.  Unless I was being careful and took them out before storage. [I'm mostly a guitarist/vocalist but want to use it for composing bass tracks. Sometimes I just lift it off the wall and twiddle an idea without an amp or do it on the acoustic but need to be sure the reach is achievable. Now I want to track it into Cubase via the USB box]. 
Thanks for confirming the black to ground. Does anybody know what exact model variation I have here if it differs from the official circuit diagram? Just in case I need circuit spec for spares in the future.



Cheers

Version III 85/86. Last one's from Matsumoku. Went to Korea after that.
Have a look on the website under Thunder Bass. There's a red one like yours.

Cheers for your very kind help. Soldered up and playing now. I just need to extend the callouses down from my fingertips! Done one quick song though.