Ever seen this? JB wiring looks weird

[Leo Huppert]

hey i finally got around to rewiring my 74 jazz and when i looked onto the control cav i saw this. i was hoping to see a black and white lead coming from each p/u (like every other diagram i’ve seen) and one ground wire to the bridge. p/ups are allegedly fralins, but i think one of them is going to need a rewind from the squirrely multimeter reading i get. any help greatly welcomed.
thanks y’all...

 

[Crater]

It looks fine... The wire color actually doesn't matter. My guess is the original bridge pickup leads got snipped and someone later soldered on some extensions to wire them back up. The neck pickup is a single wire with the exposed braided ground/shield on the outside, with the other black wire connected to the ground side of the pickup.

Except for a couple of places with burnt/melted wire insulation, it looks like a pretty good wiring job, almost OCD about the grounding and shielding.

but i think one of them is going to need a rewind from the squirrely multimeter reading i get.

Don't trust the reading until one wire is disconnected from the volume pot, the parallel resistance of the pot affects the reading.

 

[Leo Huppert]

thanks. now that i'm actually digging into it i see that the third wire from each p/up hole is a ground that connects to a plate within each pickup location. i sent for the stewmac prewired template, but that doesn't account for the control cavity ground plate. unless i'm missing something. the original reason i opted to try to rewire it was a seriously low output and thin sound from the p/ups. which is why i'm thinking i have a bad coil somewhere. in any event i'll keep plugging away. strive for tone...

 

[slightlyc]

Try switching the ground and hot wires on one pickup. If it's really thin and weird sounding they could be out of phase. With a repair and two wires the same colour for each pickup (why?) that could very will be it.

 

[Leo Huppert]

yeah i'd love to know how that happened. i got the bass about 20 yrs ago and have had new wiring installed by a great shop in nyc around that time. sounded great when i got it back and i got really nice tracks out of it over the years, which makes me suspicious that something may be up w the windings now. i definitely need to brush up on multimeter use and my soldering chops before i dive in but these days, i have a LOT of extra time on my hands....

 

[slightlyc]

Forget the multimeter for now just swap the wires on one pickup. Might work.

 

[RobbieK]

The anti-clockwise lugs of both volume pots need soldered wire connections to earth. If this has been like this for 20 years, there's a good chance, there's simply corrosion between the plate and the pot shafts/nuts causing a bad earth connection for the pickup earth wires.

 

[nycbassguy]

update- i pulled the bridge p'up out and swapped it with one i have around here. i also dropped the stewmac pre-wired harness in at the same time. result was a much fuller sound from the bridge p'up, but there is of course a bit of hum. not dependent on pickup selection or balance, and remains the same whether my hands or on it or not. next up i'll probably doublecheck the ground wires and maybe beef up the shielding like above. beautiful job btw.