Obscure Japanese wiring help

[devingrab]

https://imgur.com/gallery/cYATniU
I am trying to wire up an old Yamaha SG3 with some third-party pickups. The wiring should be similar to a Jaguar guitar (due to the tone roller pots). The pickups im using are some old Kawai pickups from a Domino California Rebel.

How do i go about wiring this? Feel free to draw up on the original photo!!!

I found a post mentioning that the Red and Black wires are the coils and the BLUE is the ground, or most likely a shield wire, not signal carrying. I don't know the differences, so any help would be appreciated. I've been very hyper-fixated on wiring this thing up so anything would help.

[Sweetfinger]

If you just have two wires, I'd use the red as "hot" or signal and the black would go to ground. If there are three, I'd still try red as hot and the other two to ground unless the Yamaha does something like series or phase reverse.

[devingrab]

If you just have two wires, I'd use the red as "hot" or signal and the black would go to ground. If there are three, I'd still try red as hot and the other two to ground unless the Yamaha does something like series or phase reverse.

This wouldn't create any humming or grounding problems with the blue wire being a hot wire as well?

[Sweetfinger]

Knowing what wire is shield and what wires are coil wires is a help. That's where even the cheapest little multimeter comes in very handy. Unless the guitar uses the pickups in series or has a phase or series option, one wire will be signal and the others will go to ground.

[devingrab]

Knowing what wire is shield and what wires are coil wires is a help. That's where even the cheapest little multimeter comes in very handy. Unless the guitar uses the pickups in series or has a phase or series option, one wire will be signal and the others will go to ground.

In the photo, The red wire and black wire are coils, and the BLUE is ground/shield/no signal. Not sure the difference between ground and shield.

[Sweetfinger]

Shielding needs to be grounded. Ground is a reference in any electric or electronic circuit. In most guitars, the shielding, pot casings, and strings are all connected to ground through the cable, which is connected to the amplifier ground, which is connected to the ground wire in the wall which is at some point in the building, literally, connected to the ground.

[devingrab]

Shielding needs to be grounded. Ground is a reference in any electric or electronic circuit. In most guitars, the shielding, pot casings, and strings are all connected to ground through the cable, which is connected to the amplifier ground, which is connected to the ground wire in the wall which is at some point in the building, literally, connected to the ground.

When grounding wires in a guitar, could you ground every black wire to the same pot? Why do most schematics have black ground wires scattered throughout the diagram?

[timtam]

I found a post mentioning that the Red and Black wires are the coils and the black is the ground, or most likely a shield wire, not signal carrying. I don't know the differences, so any help would be appreciated. I've been very hyper-fixated on wiring this thing up so anything would help.

You mentioned black twice. Did you mean blue is the ground/shield ?

In any case a multimeter is an essential tool for such determinations. Only between 2 of the 3 wires should you see the expected DCR for those pickups - then you know for sure that those 2 wires are the coil wires. If instead you measure between the shield wire and one of the coil wires, you will either get open circuit, or zero ohms (if one coil wire is already tied to the shield/ground wire within the pickup).

So in this case you should get the expected DCR between red and black.

But once you know the two coil wires, that doesn't tell you which should be hot and which should be grounded, in order to be 'in phase' with the other pickups when selected together. For that you need the 'screwdriver test' on your multimeter ... where you put a screwdriver against the top of the pickup and then pull it away. So you attach the two coil wires to the multimeter, one to the +ve terminal ('hot') and the other to the -ve terminal ('ground'). You can do the test in the multimeter's current, DC volts, or resistance mode (whichever gives the clearest result). You want each pickup pair to both deflect the reading in the same direction (positive/up or negative/down) when you pull the screwdriver away. If they do go in the same direction, then you have the hot and ground wires designated correctly for both pickups to be in phase. If not, just swap the designation of hot and ground for one pickup.

Or you can just toss a coin on which wire you call coil hot and which you call coil ground. Without knowing the provenance of the diagram, it might be a fair bet that black is coil ground for all pickups. If you get it wrong when you wire it up that way then the result will sound out of phase when two pickups are selected together ... so you then go back in and swap the two wires on one pickup. On 3-pickup guitars like this you need to be a little more careful choosing which one to flip. Also on guitars where a pickup with a metal cover/base/claw only has two wires in total.

All ground points in guitar are the same. So you can ground the coil ground and the shield wire to whatever location is convenient.

[cbrown]

viewtopic.php?t=100871

If you've not already seen this, it might help.

[devingrab]

viewtopic.php?t=100871

If you've not already seen this, it might help.

I actually have seen that. Ive also found the original schematic from the SG3 manual. I tried to wire it up to it but it didn't work for me.