Coil-tapping the humbucker. First, make sure you know which two wires make up the series link in your humbucker. The series link is the start of one coil and the finish of the other coil in a four-conductor humbucking pickup. When combined, these two wires join the two coils in series.
If these wires are grounded, one of the coils is turned off. On our PRS Tremonti humbucker, the red and green wires are the series link. Black is the primary output and white is the ground.
Grounding the red and green wires coil-taps the humbucker. Take a moment to study Image 2, which shows the 5-way switch configured for coil-tapping in position 2.
Now solder the series link wires to the top-right lug, as shown. (Again, the color of your series link wires may be different.) Then, still following the diagram, solder a ground wire from the switch’s third right-side lug to the back of one of the pots. Now position 2 runs the series link to ground and coil-taps the humbucker.
Tie up loose ends. Remember the output wire that’s still attached to the volume pot? It’s time to reconnect it. As shown in the diagram, solder it to the fourth lug on the left (spring) side.
Now we’re ready to connect the tone controls to the switch. Solder the wire for the lower tone control (tone 2) to the second left-side lug—the same lug used by the middle pickup’s lead wire. Next, solder the wire from the upper tone (tone 1) to the third left-side lug, which is shared by the neck pickup’s lead wire.
With this new configuration, the tone controls still function as before: Tone 1 is active whenever the neck pickup is selected, either solo or in combination with the middle pickup, and tone 2 is active when the middle pickup is selected.
This is how the switch should work:
• Position 1 = bridge humbucker (no tone control engaged).
• Position 2 = tapped bridge humbucker plus middle single-coil (tone 2 engaged on middle pickup).
• Position 3 = middle single-coil (tone 2 engaged).
• Position 4 = middle plus neck single-coils (tone 2 and tone 1 independently engaged on middle and neck single-coils, respectively).
• Position 5 = neck single-coil (tone 1 engaged).
To confirm the switch is working correctly, lightly tap the pickups with your hemostat as you change positions on the 5-way switch. You can test the volume and tone pots by gently rubbing the pickup pole pieces with the hemostats while turning the controls.
Once you’ve tested the switch and are satisfied that everything is right, re-attach the pickguard, string up your guitar, and enjoy the new, coil-tapped sound of position 2.
When you coil-tap a humbucker and combine it with the middle pickup in position 2, you should hear a robust dual-pickup tone—sweet, singing, and perhaps a bit clucky. If instead the sound is weak and shrill—and it lacks the punch of either the bridge or middle pickup by itself—the two combined coils aren’t in phase.
To correct this, simply reverse the lead and ground wires from the two stock single-coils—the guitar’s middle and neck pickups. In other words, unsolder the ground and hot wire for each pickup and swap their roles (the former ground wires connect to the 5-way switch and the former hot wires are now grounded on the back of a pot). The solder points remain the same, but each pickup’s two wires trade places.