Problems with switch-wiring (?) - both pickups are on in all positions

[Norba]

Hello everyone,

I've just registered recently because I have a problem that I couldn't find a solution for.
I've bought a Gibson SG Special on eBay that had it's pickups changed to Burstbucker Pro's but the nut was chipped. I tidied it up, changed the nut - for the first time ever -, set the string height and all sorts of things but now that I finally could play it I noticed that both pickups are engaged in every switch positions. What is more weird is that both tone knobs are on as well.
So I messed around and this is what's going on in each positions:

Neck: both pickups are on, both tone knobs are on, only neck volume is on
Middle: everything is on as intended
Bridge: both pickups are on, both tone knobs are on, only bridge volume is on

It seems like both tone knobs act like 5-5, so if I want full tone I have to set both of them on 10, if I want 1 I have to set both of them to 1. For 5 I guess I only have to set only one of them to 1.
Checked wiring diagrams online and the wires themselves, apart from one loose grounding wire for the neck pickup - which I soldered back - I saw no real problems. Although the capacitors connected to the bottom lug of the volume pots which I changed back(?) to the middle lug.

One other weird thing is when a string touches the pickup it shorts out everything, no sound at all. I tested on other guitar, besides the loud noise prodced by this contact the other strings should be fine and heard.

If you have ideas, suggestions, questions please don't hold back. I actually kind of enjoy doing this, a little project fixing a nice guitar.


The loose yellow wire was attached to both volume pots to ground, I changed that connection to the braided wire according to wiring diagrams - I had no better idea what could cause the problem at this point.

Thanks.

Norbi

 

[donepearce]

It is really hard to see exactly what is connected to what, particularly around the area of the centre switch contact. Maybe shoot in from the side slightly, and move the wires around so they aren't overlapping where they are soldered.

 

[Norba]

I tried to make new photos. The yellow wire on the neck side goes nowhere - it was soldered to the neck vol pot but I detached it. The yellow wire on the bridge side is soldered to the braided wire's metal shielding which is soldered to every pot and ends in the output jack. The hot wire of this starts at the bottom (from this angle) of the switch with the 2 metal sheets that are pushed together.
The switch mechanically seems to be fine, when I switch it up or down the metal sheets move and they get separated. Since the volume knobs are engaged according to the switch position it indicates to me it's fine. But somewhere some connection is messed up that I can't see.
If there was a site to design guitar circuits I'd make a drawing.

 

[donepearce]

Do you have a scanner? You could sketch it. The wire from the switch where the two pieces are bent together should go to the hot terminal of the output jack, and nowhere else. Is that how it is? The problem with the signal vanishing when you press a string onto the pickup sounds like the pickup hot is connected to cold instead, so when you touch the grounded string to what should be pickup cold, it is in fact pickup hot, and the signal gets shorted.

 

[Norba]

I don't have a scanner but the wire goes the way you described it.
I've got a tip that the pickup wires are messed up, the hot might be wired to the back of the pot and ground on the lug... I suspected that this guitar wasn't treated really well but this kind of mistake... well, I guess I shouldn't be surprised.
I googled Burstbucker pro and it seems it might be a 4 wire pickup, so it's not impossible that the wire for coil split has been used instead of the real hot wire.
Anyway, whichever is the case I better detach the pickups, check the wires and try again.

 

[donepearce]

I don't have a scanner but the wire goes the way you described it.
I've got a tip that the pickup wires are messed up, the hot might be wired to the back of the pot and ground on the lug... I suspected that this guitar wasn't treated really well but this kind of mistake... well, I guess I shouldn't be surprised.
I google Burstbucker pro and it seems it might be a 4 wire pickup, so it's not impossible that the wire for coil split has been used instead of the real hot wire.
Anyway, whicever is the case I better detach the pickups, check the wires and try again.

Yep, that tip is what the second part of my post was about. I would be tempted to unsolder everything and start again from a clean sheet. Google for a wiring diagram and follow it.

 

[cerebral gasket]

Maybe this will help...

 

[donepearce]

Yep. That is pretty much what I had in mind. Very tidy.

 

[Norba]

Really neat and clean. Nice reference for rewiring.
Just a side note: It's weird to me that the after picture has the tiny ceramic caps (if I'm not mistaken), a lot of people switch those for orange drops, bubmlebees, old russian paper in oil, etc.

 

[donepearce]

Really neat and clean. Nice reference for rewiring.
Just a side note: It's weird to me that the after picture has the tiny ceramic caps (if I'm not mistaken), a lot of people switch those for orange drops, bubmlebees, old russian paper in oil, etc.

All that matters in caps is the value. Type makes no difference. I would be tempted to use big ones to help counter neck dive, but for no other reason. (OK, that was meant to be funny)

 

[Von Trapp]

Yeah, I was just going to say. Just take it all apart and put it together again so you know it's done right.

 

[Von Trapp]

Really neat and clean. Nice reference for rewiring.
Just a side note: It's weird to me that the after picture has the tiny ceramic caps (if I'm not mistaken), a lot of people switch those for orange drops, bubmlebees, old russian paper in oil, etc.

a cap is a cap. maybe the dude that did it knows that...

 

[donepearce]

Digikey have an online schematic creator. It's a bit clunky as all online things are https://www.digikey.com/schemeit/project/

But I did this in a couple of minutes

 

[donepearce]

Oops - Small error. I forgot the ground connection to the neck pickup circuit.

 

[Chubbles]

(At the risk of starting an argument) Exactly!

 

[donepearce]

(At the risk of starting an argument) Exactly!

Oi! Who do you think you are agreeing with me?

 

[Huntroll]

Be sure to keep the selector switches output connections isolated from the switches ground terminals.

Needless to say . . .

Each pickup's output goes to its respective volume pot high.

The ground terminals go to ground.

And the output leaf tabs combine and go to the output jack's tip terminal.

 

[Huntroll]

BTW, In most cases, Tone pots don't get grounded on the low side like volume controls do.

 

[dasherf17]

Yep, that tip is what the second part of my post was about. I would be tempted to unsolder everything and start again from a clean sheet. Google for a wiring diagram and follow it.

Yep, to share a little agony with you, I wired up an LP kit... front pickup was very faint and hellacious buzz that stopped when I touched metal on it... I'm sure I crossed pickup wires and wired the jack wrong (first full wiring job)...
I'll be taking notes... best of luck to you!
Oh, and thanks for all the help i've seen while "composing"...

 

[Norba]

Hello everyone,

I posted the results here yesterday but I can't see it anymore so here it is again:
On Saturday I managed to fix the wiring thanks to the tips I got. What I found surprised me but considering the state of the guitar I shouldn't have been surprised that much.
So this is what I found after I removed the neck and bridge shrink tube from the wires of the pickups.


The ground was wired as hot and the hot was ground - as you suspected.
I changed to the correct way and now it sounds like an SG should. Who knows how long it has been since this guitar sounded properly.
To be honest for a little bit I hesitated if I should repair it. It sounded kind of Telecaster-ish - or at least single coil-ish. And since I don't have a Tele, for a moment I thought leaving it as it is but I'm glad I repaired it in the end. Now that it's done it was a fun little project. :)

Sorry, I'm not going to post a photo of the finished wiring because it's messy. I'm not really good at soldering and the tip accidentally melted some wire isolation here and there but it works.