# Seymour Duncan coil splitting explained

Canonical page: https://guitarwiring.app/wiring-guides/seymour-duncan/coil-splitting

A humbucker has two coils. See how a switch lets you use just one of them.

Applies to: Passive four-conductor humbuckers with separately accessible coil leads. This is a modification to a complete guitar circuit.

## One pickup, two switching states

In the standard series setting, both coils form the signal path. A split connection bypasses one coil. The source sheet shows two alternatives depending on which coil you want to retain.

The smooth-post row is the slug coil; the row with screw heads is the adjustable coil. “Inner” and “outer” change when you turn the pickup around, so identify the physical row first.



## Follow the series link

For the source’s slug-coil example, black remains hot and green remains grounded. Red and white go together to the switch. The split setting connects that junction to ground; the full setting leaves it ungrounded.

For the screw-coil variant shown in the source, red is hot, white and bare are grounded, and green plus black form the switched link. Grounding that link retains the screw coil. Follow this whole variant; do not mix its leads with the smooth-post example.



## Check the switch before soldering

The source labels pulled up as split and pushed down as full. Confirm the actual contacts of your push/pull with a continuity meter; rotating the component or viewing it from the opposite side can make the drawing misleading.

- Choose the coil you want to retain.
- Find the middle switch terminal and check which neighbour it connects to in each position.
- Follow one complete wiring variant, keeping the bare shield grounded.
- Check both settings before closing the control cavity.

## Try a complete coil-split circuit

The example below is a reviewed complete wiring diagram. Try its push/pull control in simulation mode and follow the connections. Its electrical checks do not predict the exact sound of your guitar.



Sources: WD_Coil_Splitting. https://www.seymourduncan.com/resources/pickup/wiring-diagrams

Independent explanation by Tinkercaster; not endorsed by Seymour Duncan.