Help with pickups wiring.

Cookiemonster

Hi. I have this cheapish guitar I got locally. And I just thought I would change the pickups to these Epiphone Probuckers I have. They seem to just have the braised wire and one other wire. I changed them over on the guitar and they seem to work ok, but when I turn down the volume there is a hum. 

So must be a grounding issue.  First am I right the the Probuckers just have the braided wire the the back of the pot and the other wire to a lug of the pot ? 

Secondly I haven’t changed any wiring so can you check the photo and let me know if you see anything 

thank you all for the help

@Icbm as you are always amazing with this stuff

Cookiemonster

https://imgur.com/a/TwNSI0f

BillDL

Did you forget to embed a photo?  We were posting at the same time.

Cookiemonster

One other thing when I opened the guitar up there was a black wire from the tone, no solder on the other end of the wire. It’s quite long and doesn’t appear to have been attached to anything. I connected it to a ground but wondered if maybe they had connected it to the bridge or a screw or something to ground it. Seemed odd but I am not very familiar with guitar electronics I am more familiar with pedal making 

Cookiemonster

@roberty hey mate, just remembered seeing you post some guitars with you doing cap wiring. Any ideas ? 

Cookiemonster

BillDL said:

Did you forget to embed a photo?  We were posting at the same time.

I was quickly trying to load it on to the site. Any help would be appreciated 

roberty

Cookiemonster said:

@roberty hey mate, just remembered seeing you post some guitars with you doing cap wiring. Any ideas ? 

Looks good but I can't see if the pot case is connected to ground in the picture?

Dave_Mc

Do you have a ground wire attached to the jack socket? Is there a ground wire coming from the bridge?

Jonathangus

What's connected to the middle lugs of the volume pots?  This would normally be the output to the switch.

BillDL

The loose black wire is most likely the ground / earth that needs to be connected to the bridge and therefore also to the strings.  What kind of bridge is on the guitar.

You didn't say what the wire was connected to on the tone pot.  The casing or one of the solder lugs?  Is that the wire that goes off the picture to the right?

I'm looking at that yellow wire / cable down at the output jack, but it's unclear from the image whether you have a live and ground wire connected to the respective lugs.

Cookiemonster

Ground from wire is from Jack goes to the switch from following it with a multi meter. There is the. Definitely a connection on the back of all the pots to ground. 

Cookiemonster

The back wire connected to the tone pot where should that go to ? Btw it’s a two volume and one tone config 

Cookiemonster

Few more photos in case it helps 

https://imgur.com/a/xPID9nB

Cookiemonster

The bridge is a TOM. It’s a Flying V style guitar. How would I attach the bridge to ground solder to one of the posts ? 

Cookiemonster

BillDL said:

The loose black wire is most likely the ground / earth that needs to be connected to the bridge and therefore also to the strings.  What kind of bridge is on the guitar.

You didn't say what the wire was connected to on the tone pot.  The casing or one of the solder lugs?  Is that the wire that goes off the picture to the right?

I'm looking at that yellow wire / cable down at the output jack, but it's unclear from the image whether you have a live and ground wire connected to the respective lugs.

https://imgur.com/a/xDbUKXo

Yes the ground and input are soldered to the Jack socket. 

I have had it playing ok. Just when I turn down the volume there is a big hum. When the pots are up to then it seems to be fine 

Cookiemonster

BillDL said:

The loose black wire is most likely the ground / earth that needs to be connected to the bridge and therefore also to the strings.  What kind of bridge is on the guitar.

You didn't say what the wire was connected to on the tone pot.  The casing or one of the solder lugs?  Is that the wire that goes off the picture to the right?

I'm looking at that yellow wire / cable down at the output jack, but it's unclear from the image whether you have a live and ground wire connected to the respective lugs.

The loose black wire is connected to the casing of the pot. Just not sure where to attach it to 

ICBM

I'm assuming you actually mean buzz and not hum (they're not the same thing ), since this is normally the problem when it happens when the volume is down a bit but not full up, so on that basis it's probably a shielding issue. If the bridge ground wire isn't connected to anything that would do it...

The wire needs to go to either the bridge post insert or the tailpiece insert - if it's been pulled out at the body end this can be tricky - you need to remove the insert from the body, poke the wire back up the hole from the control cavity, strip the end, and tuck it down the side of the hole so the insert traps it in place and makes electrical contact.

Getting the post insert out without damaging anything needs a bit of care - surprisingly, the right tool is a large claw hammer or a small crowbar . With a piece of soft wood or folded thick cardboard to protect the body, and the post screwed about halfway into the insert, use it to carefully and slowly pull the insert out of the body, watching for finish or wood lifting around the sides. To get it back in, protect the top of the insert with some wood and drive it back using a medium-weight hammer.

The wiring actually looks OK in terms of the connections - however, there is *miles* too much excess cable, which even though it's shielded, will not help. In particular the pickup cables (which could also short against the pot terminals) and the yellow cables from the switch to the tone pot and the jack are far too long - the one from the switch to the tone pot is absolutely ridiculous. (I appreciate that you probably simply left the factory lengths here - they're notorious for this.) You need to shorten them to a sensible minimum where there's enough slack that you can move the wires about if you need to do any further work, but not much more than that.

Shortening the cabling may also actually improve the tone of the guitar - it can increase clarity quite noticeably.

Cookiemonster

ICBM said:

I'm assuming you actually mean buzz and not hum (they're not the same thing ), since this is normally the problem when it happens when the volume is down a bit but not full up, so on that basis it's probably a shielding issue. If the bridge ground wire isn't connected to anything that would do it...

The wire needs to go to either the bridge post insert or the tailpiece insert - if it's been pulled out at the body end this can be tricky - you need to remove the insert from the body, poke the wire back up the hole from the control cavity, strip the end, and tuck it down the side of the hole so the insert traps it in place and makes electrical contact.

Getting the post insert out without damaging anything needs a bit of care - surprisingly, the right tool is a large claw hammer or a small crowbar . With a piece of soft wood or folded thick cardboard to protect the body, and the post screwed about halfway into the insert, use it to carefully and slowly pull the insert out of the body, watching for finish or wood lifting around the sides. To get it back in, protect the top of the insert with some wood and drive it back using a medium-weight hammer.

The wiring actually looks OK in terms of the connections - however, there is *miles* too much excess cable, which even though it's shielded, will not help. In particular the pickup cables (which could also short against the pot terminals) and the yellow cables from the switch to the tone pot and the jack are far too long - the one from the switch to the tone pot is absolutely ridiculous. (I appreciate that you probably simply left the factory lengths here - they're notorious for this.) You need to shorten them to a sensible minimum where there's enough slack that you can move the wires about if you need to do any further work, but not much more than that.

Shortening the cabling may also actually improve the tone of the guitar - it can increase clarity quite noticeably.

Amazing thank you, yes that’s all stock wiring. I assumed it was a little long. However I think I have a switch issue. I have now worked how to connect that wire to the bridge posts, so that’s a bonus. 

So tomorrow I will have another go and potentially order a new switch, although I’ve never wired one of these so might be interesting. 

On the plus note it has full sized pots which I wasn’t expecting. 

Oh and yes you’re completely right I had to use a claw hammer on the posts, I had googled that the other day. I was quite surprised by that. 

Cookiemonster

@icbm is the reason it improves tone due to the longer wires have some form of capacitor value 

ICBM

Cookiemonster said:

So tomorrow I will have another go and potentially order a new switch, although I’ve never wired one of these so might be interesting.

It probably just needs cleaning. That type of switch is very simple and reliable unless the spring leaves get bent wrongly.

Cookiemonster said:

Oh and yes you’re completely right I had to use a claw hammer on the posts, I had googled that the other day. I was quite surprised by that.

I use a crowbar. I have done it with the guitar owner watching...  

Cookiemonster said:

@icbm is the reason it improves tone due to the longer wires have some form of capacitor value 

Yes, exactly. The electrical value is very small, but it seems to make a surprisingly large difference.