Wiring not working, where did i screw up?

[give me the toan]

I've finished soldering together a dual-humbucker setup with 2 Mustang switches each for Series/Split/Parallel as shown in the wiring diagram:

Unfortunately I found some issues:

-I wanted the volume knobs to only control 1 humbucker each, but it turns out they each control both humbuckers.
-My split option isn't working. I'm getting sound from the pickups by tapping them, but in the middle position i can hear both coils as being active.

Could I get some help troubleshooting?

 

[give me the toan]

Oh, and here's the link to the original diagram: https://www.offsetguitars.com/forum...id=f887f0f71f13b3c1bb0ec8a29c6344be&start=555

 

[KokoTele]

What's more important is to see what you've actually done, not what you tried to do ;-)

Your best trouble shooting tool for this kind of thing is a meter with a short detector. Clip one lead to where your signal starts, and then touch the other lead to each point it *should* go to in sequence. It beeps when it detects a short, so you know you have a connection. At some point, you'll follow a signal path and find you don't have the connection you need. If you don't have a meter that beeps, just use a meter in resistance mode and look for 0 resistance at the connections. If you don't have a meter you don't really have the tools you need for the job and should get one, but you can trace your wires visually too.

It's also a good strategy to disconnect one pickup and its controls and work on just one pickup at a time. When you get the bridge pickup (for instance) working properly, then work on the neck pickup.

 

[peterg]

Try swapping the in and out wires on the volume pots.

Edit. See jazz bass wiring for details. Each pickup/pot should be isolated. The output from the pots feeds the tone pot.

 

[kbold]

Only had a momentary glimpse of the cct:
The tone section is linking the p/u outputs together: I think that's the problem.
Try disconnecting the tone part (and the link between the pots) and see where things stand.

 

[give me the toan]

Try disconnecting the tone part (and the link between the pots) and see where things stand.

Just did that, like in this diagram:

However, the "both volumes control both pickups" problem remains. I believe this is because they're linked at the output jack, and from what I just looked at for Les Paul wiring, it appears to go to the pots first, then the selector switch. Not sure how I'd do something like that however.

 

[peterg]

Your diagram doesn’t show a pickup selector switch - just series/single/parallel switches.

 

[give me the toan]

Try swapping the in and out wires on the volume pots.

Edit. See jazz bass wiring for details. Each pickup/pot should be isolated. The output from the pots feeds the tone pot.
View attachment 986747

So I need to feed the first volume pot into the next one, then into the tone and jack?

 

[AAT65]

1) the left-most wire from the pickup needs to go to ground. It might be linked there already if it's connected to the base.
2) as @peterg has said, you need to swap the volume wiring to J-Bass style -- pickup to centre lug (wiper), output from the non-grounded end lug.

 

[give me the toan]

1) the left-most wire from the pickup needs to go to ground. It might be linked there already if it's connected to the base.

I need to join the south start with ground? If so, at which lug?

 

[AAT65]

I need to join the south start with ground? If so, at which lug?

Yes, I believe the South + needs to be grounded.
Grounds can go wherever you like / is most convenient. There's only one ground in this circuit (and in the end it's got to be connected to the output jack).
Try tracing the signal path for one pickup from the volume (which is the output from the pickup) through the switch, in its different positions, & the two coils. Your journey needs to end at ground.
And please take @KokoTele's advice and buzz it out with a multimeter / continuity checker!
A

 

[eallen]

As @KokoTele said, post a pic of your wiring so we can actually see what you have instead of what it is supposed to be. It is usually something simple someone can clear up with one reply once you do.

 

[give me the toan]

I've just done the Jazz Bass wiring for the pots which solved problem 1! I also grounded the south start wire on the humbuckers, but I can't tell if only one coil is active by tapping it. Will be posting pictures once possible.

 

[give me the toan]

Alright, got pictures of one of the switches:

And the control plate area:

 

[peterg]

Re: pot tabs opposite the output tab. Are they grounded? They should be. A short piece of wire from the tabs to the back of the pots will suffice. Alternatively extend the wire already soldered to the tabs to the backs of the pots.

 

[peterg]

deleted

 

[hotdotdog]

I've finished soldering together a dual-humbucker setup with 2 Mustang switches each for Series/Split/Parallel as shown in the wiring diagram:

View attachment 986717

Unfortunately I found some issues:

-I wanted the volume knobs to only control 1 humbucker each, but it turns out they each control both humbuckers.
-My split option isn't working. I'm getting sound from the pickups by tapping them, but in the middle position i can hear both coils as being active.

Could I get some help troubleshooting?

You have a bad wiring diagram to work with. It ties both volume pots together (see attached). Find a better diagram. Seymour Duncan's site has good ones.

 

[nikonmikon]

but I can't tell if only one coil is active by tapping it.

there's a trick i use, i have a pack of metal forceps (big tweezers for tool use, non cosmetic) and grab one by the very very end where they meet and i tap one of them on the desk like a tuning fork. they vibrate like crazy. then i turn it so that one of the tines of the "fork" is above the other and hover it over the coil i want to test. it's very important that you don't have 2 vibrating tines over each coil, hence turn it sideways so that one tine is above the other. vibrating metal over a coil makes it VERY EASY to hear which coil is active because it's a constant signal instead of tapping which is very microphonic.

you can try cosmetic tweezers too but honestly if you don't have a set of tool tweezers you are severely affecting your well being. these are hands down the best tool i own. i literally use them every friggin day.

of course if you have a real tuning fork use that. way better. good luck

 

[mistermikev]

I've finished soldering together a dual-humbucker setup with 2 Mustang switches each for Series/Split/Parallel as shown in the wiring diagram:

View attachment 986717

Unfortunately I found some issues:

-I wanted the volume knobs to only control 1 humbucker each, but it turns out they each control both humbuckers.
-My split option isn't working. I'm getting sound from the pickups by tapping them, but in the middle position i can hear both coils as being active.

Could I get some help troubleshooting?

well... haven't gotten very far and... lets say you start in singl mode on that slide switch... you have the live on the first coil going to live, then on the backside of that coil it is going to connect to the frontside of the next coil as if we are trying to do series... but then the back side of the secondary coil is going nowhere... well that would not make sound.
similarly in the series schema... start of coil one hardwired to live, backside connects over to start of secondary coil... then the end of that coil goes nowhere. no worky. at some point a coil must go to ground for it to worky. hope that helps.

 

[mistermikev]

looking at the orig drawing which is terrible btw... i think they fully intended to wire the finish on the secondary coil to ground... and they would be bringing that ground over to the switch. so... probably would worky if you wire that to ground (if seymour code that'd be green).
yup, assuming you have wired it accurately to your orig drawing... if the leftmost wire of the south coil for each pickup is sent to ground... it will work as drawn.