G&L JB-2 Grounding Issue?

So. I think my new G&L has a grounding issue. Plugged in with the amp on, it is VERY buzzy. More so than just regular single-coil pickup noise. When I touch the strings or the bridge, the buzz goes away. My understanding is that’s a grounding issue.

Here’s a picture of the electronics cavity:

I think that there isn’t a ground wire going to the pot on the right. I can see the ground going to the left pot, the center pot, and the jack, but I don’t see one going to the right.

Hopefully, someone here with better eyes than I’ve got can confirm that. :slight_smile:

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Red is the ground here (odd color choice).

What’s connected to the top post of the tone pot? Can’t see anything.

Hard to tell but looks like the bridge ground is connected to the middle pot, is that correct?

I don’t see anything too obvious. Are all the connections solid?

Also assuming that’s shielding paint.

That’s an awful lot of wire for factory pickups. Wonder if they were replaced.

It looks like the red insulation contains a white and a bare ground wire. Do you have a multimeter to check continuity?

It could just be 60 cycle hum. Use a multimeter to run a continuity test between the pots and the bridge to make sure your bridge and strings are grounded properly.

I’m assuming that as well.

The bass was BRAND NEW. It still had all the plastic on the pickups and electronics cavity cover. It was removed from the box to tune and photograph. So, doubtful. Possible, because I don’t know what happened to it before I got it, but not probable I don’t think.


So, I found this on the bassesbyleo.com site:

It’s supposed to be the wiring diagram for this model as drawn by Paul Gagon, who worked directly with Leo Fender on these instruments. But yeah, that does seem to be a lot of wiring.

It looks like the black and white coming in in the upper left are from the neck pickup. The yellow and black coming in from between the first and second pots are from the bridge pickup. The white and yellow from the pickups go to the middle post on the two volume pots. So that matches up, I suppose.

The red wire in the picture is shielded. It goes from pot to pot to pot, making no other connections except to the pots; the shielding is soldered to the pot casing, the shielded wire to the first post of each pot. The shielded wire is white, so I guess that matches the drawings.

The white wire in the drawing from the jack to the tone pot actually goes to the neck volume pot. But that should be OK, it’s still in line with the shielded white wire as it solders to the same post. The black wire in the drawing from the jack to the tone pot actually goes to where the black wires are at on the bridge volume pot, and from there a black wire goes out to the bridge. So in contrast to the drawing, that black wire is not connected to the tone pot, or the neck pickup pot.

And, in fucking with this, the black wire coming in from the bridge pickup broke off. I think that it was not soldered properly.

So I’ve got two issues that I can see:

  1. The bridge pickup ground was not soldered well and is now off, and…
  2. Where the drawing shows a black wire connecting all three pots, the bridge, and the jack, in reality it’s only connecting the jack, one pot, and the bridge.

I know I’ll have to fix the bridge pickup ground. Should I change the black wire going to the bridge to hit all three pots as shown in the drawing?

Sadly, I don’t. I’m going to have to pick one up now, though, to check my work. Plus, it’d be good to have. My son might have one, though, I’ll have to check with him.


I don’t think it is. It’s a definite electrical buzzing, which is different from the 60 cycle hum I get on my other single coil bass. Plus, I don’t think 60 cycle hum cuts out when you touch the strings or bridge, does it?

After looking closer, the red wire has both white (hot) and unshielded wire (ground) inside of it. That does not look like factory work to me. That is the worst “factory” wiring I’ve ever seen. Either a late Friday afternoon bass, or someone had their dirty paws in there before you bought it.

Every guitar / bass I’ve opened up has black as the ground wire. @RuknRole is right I think someone might have wired that bass and quit the same shift. Sorry.

I don’t think that’s the issue. I’ve confirmed with the music store I got it from that it was brand new. And if you look at the original drawing, the ground has to be the black wire going out to the bridge, which is black in my bass (it’s just missing a pot or two). But it’s the only thing connecting the bridge to the shield of the jack. That red wire in the picture isn’t doing that.

What you’re seeing as the red wire, when looking at the original drawing, is the line that takes the output from the pots to the jack; it shows as white in the drawing, but it’s a shielded red wire in the bass. That is going from third post on neck pot, to third post on bridge pot, to third post on tone pot, and then to the jack. It’s just shielded is all. That doesn’t connect to the bridge at all, even in the drawing, so couldn’t possibly be ground.

I’m pretty sure this one does too. It comes in to the cavity from the bridge, goes to the bridge volume pot, and then to the shield on the jack. I really don’t think that the red wire is the ground.

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The red wire has both hot and ground in it Your pots look to be grounded correctly, just not using separate wires as shown in the diagram.

This what I see too.

I think I see the black ground wire going from the output jack to the shielding paint in the cavity?
It looks like the red wire has two wires (like @RuknRole stated) one of which appears to be an unshielded ground.
So if the unshielded wire connects the three pots. Then where does that go to ground?

The wires are so long it’s hard to tell we’re there going. I think the pots are doubled grounded, via black wires and via red wire. I’m willing to bet a dollar that red wire is not from factory.

No, it’s going from the Jack to the middle pot, then put to the bridge.

It doesn’t, because I don’t think that’s ground. Ground is black, but it was wired wrong. It isn’t hitting all the pots like it shows in the original drawing. I think that’s the problem.

Tim, from what I see in the picture, your pots are grounded properly via the ground wire inside the red shielding.
Take it back to the store and let them check it . Maybe even compare it to another bass and see if it looks the same.
What model is it?

Your issue is the bridge ground wire.

That diagram is the diagram for every PJ /JJ standard bass with vol vol tone. The sketchiness of factory wiring is fine, just not how I’d do it. I’ve actually seen cheesier from factory wiring on more $$ instruments.

Agree. Take it back and stand there while they fix the bridge ground and let them check all the rest. It’s a new bass.

Btw - I was sold a “new” albeit “ new old stock” bass that i swear wasn’t new from the wiring but the store swears up and down it was new.

Good help is hard to find in the soldering department apparently.

Ok I saw it was a JB2. I found a wiring picture on Talkbass. Looks like the red might be from factory. Guess I owe somebody a dollar. Lol
That one has green and dual grey wire as well. Some clown wiring going on at the factory if you ask me.

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To me it’s either a bad contact from ground wire to the bridge (bad solder joint that broke) or under the bridge ( its usually just sandwiched between bridge and body), or bad 60 cycle hum.