how can i fix my bass guitars electronics wiring? I have a disconnected jack and ground wires that need sorting

I have a bass with some wires lose in its wiring.

the output jack has come off- there is a red wire and a white wire going to it, i know where the red wire goes because that came off whilst i was fiddling, i presume the white wire goes to the only other contact?

Also as well as the red and white there was two bare ground wires that had snapped off inside the heatshrink, where should they be connected to?

Also the ground wire that goes under the bridge is lose, i need to know where that goes.

The thing is that the only place i can see broken wires from the solder blobs on the jack is where the white wire should go but that would mean the white wire + 3 ground wires all soldered to the same contact, does that sound right?

Hopefully the pictures will help you imagine the situation a little better, as i haven't described it very well.

Thanks to anyone who helps


Picture of how can i fix my bass guitars electronics wiring? I have a disconnected jack and ground wires that need sorting
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gmoon7 years ago
A photo of the entire wiring harness (including the pickups) would be helpful. OK--now I see you wrote below you have two pickups. That helps, but complicates matters.

Also, the color of the wires isn't that important-- if we can't see what they are connected to. There should be color standards for guitar wiring, but there aren't any. The color may be helpful; for instance if both pickups are identical. So a wider scope photo would be great.

Is there a pickup selector switch? We can't guess this information...

And what does this mean?:
Also as well as the red and white there was two bare ground wires that had snapped off inside the heatshrink, where should they be connected to?
Are the red and white wires shielded? What does "the heatshrink" refer to?

Given all that, there is a lot you can deduce:

-- The grounded wires for your guitar will always share a common connection somewhere in the guitar. So the ground for the bridge will connect to the other grounds. It's best to connect them together at a single point (called a star ground.)

-- Wires soldered to the body (case) of the POTs? Those will be ground connections, also (utilizing the POT case as a shield.)

-- The plug shaft of your guitar cord is always the ground. So the "collar" of the jack is the ground connection (and the tip/tab is the signal.)

I can see I haven't really helped you much, but there are many variation of pickup wiring. Without seeing more of the harness, that's about all I can do...
mdog93 (author)  gmoon7 years ago
that has helped a lot.

couple of things:

*No there is no pickup selector switch
*The red wire is connected to the volume POT, and the white wire is connected to the tone POT
*As for your question, heatshrink is a platics tubing use to protect and gather wires and also to protect solder points from shorting with others. (in short, it doesn't make a difference to the circuit)
*The ground wires are 'bare' meaning there is no plastic insulation around them

I will add some pictures to try and clear up a few of your queries.

ok i cant add labels to these images so:

1)The first image shows both POTs, the one on the left is the volume and the one on the right is the tone. As you can see on the nearest contact pad on the volume POT there is a red wire this is the wire i was referring to erlier, soldered to the top of that POT is the ground wire soldered that you can just see on the far side of the volume POT.

On the right is the tone POT, again on the closest contact you can see the white wire i mentioned erlier on. Also on the near side of the tone POT this time is the second ground wire soldered to the housing of the tone POT.

2)The second picture is just to give you a vague idea of the pickup array
3)A close up of one of the pickups (i think that is the one closest to the bridge

4)Is a rather blurry close-up of the volume potentiometer- you can see the ground and white wire from the pickups (wrapped in blue insulation), the red wire and the other ground wire which leads to somewhere on the jack.
5)A close-up of the tone POT, you can see the white wire, the ground wire, and the capacitor


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gmoon mdog937 years ago
Well, that helps--some. A single, clear, inclusive photo would also show relative wire lengths, which can be a helpful clue.

Unfortunately, I can't tell from the photos:

1) Are any of the POT tabs soldered to the cans (themselves), I.E., grounded? If so, which ones?
2) Which POT tab is the pickup signal wire (white wire from the blue shielded cable) connected to? (center or end?)
3) Are any of the POT tabs "bridged"--connected together with a wire or a solder blob?

Re: "heatshrink"--I know what heatshrink is, I still don't know what "the heatshrink" refers to in your context... XD... Is it:
-- the insulator on a shielded cable?
-- Ground wires bundled together?
-- or something else?
You claim it's unimportant, but that two wires have "snapped off" inside? Sorry, I can't reconcile those two conflicting facts (broken connections--that don't matter.) Or picture it from your description... It was likely there for a reason.

I can see some things:

Your two pickups are wired together in series. They appear to be connected to the volume POT via a Blue shielded cable. The GND connection is soldered to the POT can; the other side I cannot see (see question 2 above.)

And the tone capacitor is soldered to the POT center tab; and other side to the POT can of the tone POT (grounded.)

My guess (which is based on limited "intel"):
-- Both the Red and White wires connect together on the signal tab of the output jack.
-- The other two ground wires connect together on the the GND (ring) of the jack.
-- The third ground (bridge) connects to the solder blob on the volume POT.
-- The dreaded "heatshrink" may have bundled the ground wires together, or it may have bundled ALL the wires together that lead to the jack (GND leads acting as a primitive shield around the insulated signal leads.)

mdog93 (author)  gmoon7 years ago
sorry, i was trying to help lol, but seem to have complicated things.

Both POTs are grounded via the far tabs, (the ones you couldn't see) or the one furthest from the red wire on the volume POT and the white wire on the tone POT and vise versa.

The signal wire from pickups is soldered to the centre tab on volume POT

No, none of the POT tabs are soldered to each other, just the end ones soldered to the housing.

Sorry, the heatshrink bundle the red, white and two ground wires together leading off towards the jack connector. I didn't mean that the wires weren't improtant i meant that the actual heatshrink doesn't directly affect the circuit.

You won't see the heatshrink because i had to cut it off to reveal why i could see four wires going into the heatshrink tubing but only see two coming out.

And from what i can see myself it looks like the bridge ground was simply connected to the same output jack tab as the other grounds. I don't know enough about guitar electronics in particular to know whether that could be correct or not.
gmoon mdog937 years ago
Hey, no biggie.

With the POT tabs grounded as you describe, the White wire can't be a ground--the tone control would be connected to GND at both ends, and do nothing. Since you know the White wire leads to the jack, it must connect with the Red wire on the "tip."

My guess is essentially correct, I think.

Doesn't matter whether the bridge ground is connected directly to the jack GND or to the volume POT can--either way, it's grounded. I was just trying to account for the unused "blob" on the POT.

If you think that wire is routed directly to the jack, you're probably right. But either way would be identical on a schematic.

How the grounds are connected together can have a large effect on noise, however. Not that no-name guitar manufacturers paid much attention to that...
mdog93 (author)  gmoon7 years ago
yeah so i didn't think the white was ground, but i presumed that meant it would have to go to a different tab to the red, i presumed that both tabs were for the pickup i.e. it is a sterio-output, but now i presume it must be mono?

Yeah i might extend the bridge ground to the pot, would tidy things up near the jack, but the blob of solder doesn't have anthing snapped off in it but that's besides the point.

and as for the noise i will deal with that after i get the thing working, cause if no sound is coming out there is no point fixing the ground yet.

Is the ground connection on the jack the one anti-clockwise from the big long tip connector?
gmoon mdog937 years ago
It's tough to tell from the photos, but one of those tabs will be directly connected to the "ring" that encloses the shaft of the plug. That's the ground. In the second photo (in the original posting at top), it sure looks like the bottom tab is the ground tab.

You should be able to visually trace the metal parts, and where they connect in the jack. If not, time to buy a cheapo VOM (volt-ohm meter) at Walmart, and use the ohmmeter as a "continuity tester."

Definitely NOT a stereo output--there are only two connectors on the jack--shaft and tip. Stereo requires three connections (right, left, ground), and a TRS plug and jack.

The White wire connects directly to the Red because that's the way tone controls work--they "shunt" high frequencies away from the signal, through the capacitor on the tone POT, and away to the ground. The less resistance between the signal and the cap/GND (as you turn the tone POT), the more high frequencies slip away from the signal.
mdog93 (author)  gmoon7 years ago
cheers, what i will do the at the weekend is solder the red and white onto the tip connector and see if i can get sound out of it. then if i do i will sort out the ground.

Does that sound like a good plan?
gmoon mdog937 years ago
It's a plan ;-).

You'll never get a signal without a ground, though. All electrical circuits need a "return path" for current.

The ground for bridge, however, is ONLY for noise suppression. When the bridge is connected to the ground, your body acts as a shield (that's why your guitar is quieter when you're touching the strings...) So if "sorting out the ground" refers only to the bridge, then you're good...

Good luck, BTW.
mdog93 (author)  gmoon7 years ago
YEAH BABY! I got it to work, thanks for all your help, i just got it working and teted it and it worked then i snapped another wire and thought, rigght ok back to the soldering iron all i gotta do now i find screws to replace the ones that are missing.

Any ideas what the type of screw is that alters the pickup height cause they aren't normal screws?

I lost a screw which holds the cog onto the tuning peg, and i'm sure it can't have been there for a while otherwise i would have picked it up when i heard the cog fall off.

hopefully i will be able to find a replacement
gmoon mdog937 years ago
Cool--rock on, man.

Missing screws: if you're extremely lucky, you might find some replacements at a real hardware store (not a chain.)

In my experience, the screws on musical instruments are always a weird diameter or thread pitch, though. It's more likely you'll have to go to a music store for that stuff..

I've got a bucket of old hardware from "totaled" guitars, but I still have to hit the stores to find stuff periodically.
Re-design7 years ago
Google "bass guitar wiring" and you will get some sites to get you started.

Add the name of your guitar and my might find the exact schematic for your guitar.  Since you didn't give it I can't try it myself.

How many pickups?  Any on guitar controls? 

It is very possible that the white and grounds all came off the same connection but impossible to tell from here.
mdog93 (author)  Re-design7 years ago
ok, thank you. I did try googling it couldn't find one similar to mine and i can't google the guitar name because i don't know it!

It is quite an old guitar with no name, maker or model printed anywhere on it, i suspect it was just a cheapo thing when new.

It has two pickups, a volume control and tone control.
mdog93 (author)  Re-design7 years ago
yeah i saw that, only it does't say where the white wire would go and also i don't know enough about grounding to know where to ground things to.
The ground eventually gets pinned to the ring of the phone jack. 
mdog93 (author)  Re-design7 years ago
ok thanks, so if i do solder all the grounds and the white wire to the same contact, you don't see any reason why it shouldn't work