Wiring weirdness on G&L Tribby JB-2

[andydye]

I got a lovely JB-2 Tribby recently and it plays and feels really good (especially for the money!), only snag is that the neck pup does nothing, not even a crackle when I turn the pot, nothing!!

I've been sent a replacement pup and vol pot from the retailer but on opening it up the wiring doesn't look like any jazz bass wiring I've ever seen (or like the JB-2 wiring diagram that's on the G&L website!)...there are more wires from the pickups than the replacement I've been sent too!! It's confusing my little non-electrical brain!!

Here's a link to the G&L JB-2 wiring diagram
[url="http://www.glguitars.com/schematics/JB2_schematic_drawing.pdf"]http://www.glguitars.com/schematics/JB2_schematic_drawing.pdf[/url]
It looks enough like a standard Jazz bas wiring diagram that I recognise it!

Here's a pic of the wiring on my JB-2
[attachment=130569:20130319_195822.jpg]
All of the black wires from the pickups along with the earth that goes to the bridge and the tip connection for the jack socket are soldered to the top of the casing for the neck pickup pot!

The white wire from the neck pup goes to the middle peg of the neck pot (looks normal to me)
The yellow wire from the bridge pup goes to the middle peg of the bridge pot (looks normal to me too)
A green wire goes from the bottom peg of the bridge pot to the middle peg of the tone pot (this doesn't look right to me but the tone pot works for the bridge pup so...?)

I've sketched a schematic of what the wiring actually does (hopefully it makes some kind of sense)
[attachment=130570:20130320_162450.jpg]

Questions...

Is there any wiring reason why the neck pup does nothing at all?

Should I rip all the wiring out and start again with a more standard jazz bass wiring setup? (I'm tempted to do this so I can get some better pots in there)

What checks should I be doing with a multimeter to work out whether it's th epickup or the pot that's faulty (if the wiring looks ok)?

thanks bc

[KiOgon]

It all looks pretty normal factory standard mess

The GL drawing is fine, follow that & you'll be OK, your sketch I'm not seeing very well.

All the blacks to 1 common point is fine. All you need to do is desolder the existing neck pick up wires & replace with the new - what's different about the new pick up wires?

The white, yellow & green wires you describe sound right.

Meter set on suitable range < 1000K check the pick up wires (after disconnecting) & compare to the new - probably 10K ish. Also check the pot across the 2 outer tags should be 250 K ish from centre tag to either outer, turn 1 way to zero, other way to 250 K.

[andydye]

[quote name='KiOgon' timestamp='1363798448' post='2017861']
It all looks pretty normal factory standard mess

The GL drawing is fine, follow that & you'll be OK, your sketch I'm not seeing very well.

All the blacks to 1 common point is fine. All you need to do is desolder the existing neck pick up wires & replace with the new - what's different about the new pick up wires?

The white, yellow & green wires you describe sound right.

Meter set on suitable range < 1000K check the pick up wires (after disconnecting) & compare to the new - probably 10K ish. Also check the pot across the 2 outer tags should be 250 K ish from centre tag to either outer, turn 1 way to zero, other way to 250 K.
[/quote]

Thanks matey, am reassured that the rest of it looks functional if lacking in elegance!

I'll try the new pup and see whether that cures the ill!

The new pup I've been sent has one white and one black wire (normal-ness abounds here) the pups that are installed have one white and 2 black wires each...what confuses me is that the new one isn't identical to the ones that are installed...?!