Wire disconnected in Squier Jaguar bass, what is this wire for?

[shoulderpet]

Hi

I see to have a black wire disconnected in my Squier Jaguar bass, was just wondering what this wire is for it seems to be conncted to a washer like metal fitting (see pic) that screws in to the body but the other end seems to have come loose from whatever it was soldered to, I have output as normal from both pickups, hoping someone can shed some light on this , thank you

 

[lownote]

bridge earth?

[yorks5stringer]

Go onto the Fender/Squire site  or Goggle and you'll find wiring diagrams for Jaguars. Definitely from an earth to the body so you just need to follow it back, if there is not a  loose black wire in the control cavity it could be the bridge wire which sits under the bridge. If you have no buzzing ( which should go away when you touch the strings) then maybe it is still connected at the other end?

[Trueno]

I have something similar in my MIM Mustang (but not in my Squier Jaguar for some reason). I presume it's an extra earth to the body... in addition to the bridge earth. It attaches to the same place as the bridge earth... at least it does on mine.

If you leave it unattached and have no earthing issues (assuming you still have a bridge earth) then I assume there is no need to connect it... but I'm not an expert on these things.

Edited May 13, 2020 by Trueno

[shoulderpet]

Thanks for the replies , following the wire back it looks like it is probably a ground wire as suggested, the bridge pickup has both of its wires soldered to the volume pot and it looks like this one is supposed to be soldered to the back of the tone pot.

As the neck pickup has a groud wire do I still need this one? I assume so as I assume you need a ground right at the end of the circuit?

Also as I could not do a goods solder joint if my life depended on it is there any other way I can attach this to the back of the tone pot? I nearly just tucked it under the metal control plate but then thought that as the other end was not connected to a tone pot then this will not work

Edited May 13, 2020 by shoulderpet

[Waddycall]

 it’s to ground the shielding in the pickup cavity and probably does go to the back of a pot. If you’re not able to solder it back on I’d leave it as it is unless you get issues with noise. You could cut another ground wire and connect it in with that using a screw connector etc but if some of the solder joints aren’t great you might disturb something else in the process.

[BassBunny]

18 minutes ago, Waddycall said:

 it’s to ground the shielding in the pickup cavity and probably does go to the back of a pot. If you’re not able to solder it back on I’d leave it as it is unless you get issues with noise. You could cut another ground wire and connect it in with that using a screw connector etc but if some of the solder joints aren’t great you might disturb something else in the process.

Beat me too it.

[shoulderpet]

Thanks for the replies, time for me to look into a solderless wiring harness I think 

[shoulderpet]

6 hours ago, Waddycall said:

 it’s to ground the shielding in the pickup cavity and probably does go to the back of a pot. If you’re not able to solder it back on I’d leave it as it is unless you get issues with noise. You could cut another ground wire and connect it in with that using a screw connector etc but if some of the solder joints aren’t great you might disturb something else in the process.

Thanks, would it not be a bit of an electrical hazard to leave it disconnected? 

[Waddycall]

Can’t see how. It’s there to help the shielding prevent hum/noise that’s all.

[Trueno]

3 hours ago, shoulderpet said:

Thanks for the replies, time for me to look into a solderless wiring harness I think 

A KiOgon loom would be a win/win situation.

[shoulderpet]

58 minutes ago, Waddycall said:

Can’t see how. It’s there to help the shielding prevent hum/noise that’s all.

Ok, I thought a ground wire was to prevent any possible electric shock ? 

Found this on Dealings website which seems to confirm this:

A Ground Connection connects every piece of metal on your guitar and acts as a return path to the amp. In part, the Guitar's Ground Connection helps remove unwanted noise, and is essential for safety – It allows electricity to travel safely to the amp to dissipate

Edited May 14, 2020 by shoulderpet

[Waddycall]

The ground wire for the cavity shielding is to remove any potential that builds up in the shielding stopping it from preventing noise induced by outside interference.  Some bass’s don’t even have that wire. The rest of the bass is still grounded via the pots, bridge ground wire etc.

Theres also the theory that the ground connections can electrocute you if you have an amp fault! Some people recommend fusing the ground wire.

P.S. I’m on a steep learning curve with guitar electronics myself but would have no safety concerns about leaving that disconnected.

[shoulderpet]

46 minutes ago, Waddycall said:

The ground wire for the cavity shielding is to remove any potential that builds up in the shielding stopping it from preventing noise induced by outside interference.  Some bass’s don’t even have that wire. The rest of the bass is still grounded via the pots, bridge ground wire etc.

Theres also the theory that the ground connections can electrocute you if you have an amp fault! Some people recommend fusing the ground wire.

P.S. I’m on a steep learning curve with guitar electronics myself but would have no safety concerns about leaving that disconnected.

Ok thank you for the confimation, good to know that this would not be a hazard, I remember reading once that a bass only needs to be grounded (to protect against electric shock) in one place so what you have said seems to make sense. 

Having a look at the control cavity of my bass there is a black wire soldered on to the back of the tone pot so looking at the Seymour Duncan wiring diagram it would seem that this is the wire that grounds against the bridge, I had a look and the black and white wires from the bridge pickup are soldered to the bridge volume pot so this seems to further confirm this , I think I will  wrap some electrical tape on the end of the disconnected wire and call it a day  , thanks for the help

 

   

[Stub Mandrel]

2 hours ago, shoulderpet said:

Ok, I thought a ground wire was to prevent any possible electric shock ? 

Found this on Dealings website which seems to confirm this:

A Ground Connection connects every piece of metal on your guitar and acts as a return path to the amp. In part, the Guitar's Ground Connection helps remove unwanted noise, and is essential for safety – It allows electricity to travel safely to the amp to dissipate

That is a very poor description.

The ground does act as a return path for signals and shields from noise,

The earth connection in the amp (unless it is double insulated and super safe) should be connected to the earth in the mains plug and if it becomes live due to a fault its function is to pass enough current to blow the main fuse.

Grounding the guitar itself makes no great difference to this protection as modern amplifiers are constructed so that it is virtually impossible for the instrument connections to become live (sadly this wasn't the case in the old days when a few people got electrocuted by valve amps).

That said, it is still important to have the guitar's metal parts connected back to earth, but mostly in case they get connected to something else that is live (ironically there have been cases of a microphone being live and a guitarist being killed as the become the path to earth via their guitar).

But... as the shielding is inside the guitar it plays no practical role in safety and is there solely to reduce hum, or clicks when you pick up the guitar.

[Stub Mandrel]

1 hour ago, Waddycall said:

 Some people recommend fusing the ground wire.

PLEASE NO!!!

In a proper installation there will be a fuse in the right place. If an earth fuse fails there is then (a) no protection in the case of a fault and (b) no path for enough current to flow to blow the main fuse. Double fusing is not double protection as my Dad (a working lifetime in electrics) drummed into me.

But a lethal electric shock is milliamps, it probably take 20 amps to blow a 13A fuse promptly - those fuses are to prevent fires under short conditions, not protect from electric shocks.

This is also why if you go to a venue make sure there's a RCB for the outlets you use and test it - back in the day before this became a legal requirement I always used a stand alone one for my gear and now I have fitted an RCD to my extension lead.

An RCD will trip on less than 40mA leakage - enough to prevent a lethal shock.

[Waddycall]

Check this out!

https://www.taylorguitars.com/taylorware/string-ground-fuses/universal-string-ground

[Stub Mandrel]

14 minutes ago, Waddycall said:

Check this out!

https://www.taylorguitars.com/taylorware/string-ground-fuses/universal-string-ground

That's the exception that proves the rule.

It's a 5-10 mA fuse to stop electricity coming from amp to guitar rather than a fuse in the earth connection of an amp.

Such a fuse could offer protection IF the earth of the amp was faulty/disconnected BUT and its a BIG BUT:

It might stop the strings becoming live but it sure as hell ain't going to stop your guitar lead going live if the fault is coming from your amp so be prepared to be zapped when you unplug your lead....

Also, apparently the thing that kills those expensive fuses is plugging them into the switched side of a stomp box with a battery in...

http://dthompson55.blogspot.com/2012/03/problem-with-taylor-guitars-fused.html

(By the way it MIGHT have saved Moby the experience related but as his shock was non-lethal it's quite possible it was too small a current to even blow the Taylor fuse... 6-16mA is enough to give a painful shock and a 5-10mA fuse would probably need 10--20mA to fuse instantly).