# One P-Rails, on-off-on mode switch, volume

Canonical page: https://guitarwiring.app/wiring-diagrams/seymour-duncan/one-p-rails-on-off-on-volume

One P-Rails · On-off-on mode · Volume 500k

One P-Rails, on-off-on mode switch, volume. Transcribed from the manufacturer wiring sheet.

Drawing: https://guitarwiring.app/wiring-diagrams/seymour-duncan/one-p-rails-on-off-on-volume.svg (back of controls)

## Parts and values

- P-Rails: P-Rails; generic (P-Rails stand-in (four-conductor))
- Rail / humbucker / P90 on-off-on: Rail / humbucker / P90 on-off-on; compatible example (DPDT Mini-Toggle (on-on-on))
- Volume 500k: Volume 500k; 500k; compatible example (CTS 500k Audio Pot)
- Output jack: Output jack; compatible example (Switchcraft \#11)
- Bridge ground: Bridge ground; generic (Bridge ground wire)

## Specific to this wiring

- P-Rails drawn as generic-p-rails-four-conductor with Seymour Duncan lead colours on the sheet.
- On-off-on legend: up rail, middle humbucker, down P90.

## Connections

1. P-Rails gnd → Rail / humbucker / P90 on-off-on T5 (wire, green)
2. P-Rails bare → Volume 500k casing (wire, bare)
3. Rail / humbucker / P90 on-off-on T5 → Volume 500k casing (wire, black)
4. Volume 500k lug1 → Volume 500k casing (wire, ground)
5. Output jack sleeve → Volume 500k casing (wire, black)
6. Bridge ground ground → Volume 500k casing (wire, black)
7. P-Rails hot → Rail / humbucker / P90 on-off-on T1 (wire, black)
8. P-Rails white → Rail / humbucker / P90 on-off-on T3 (wire, white)
9. P-Rails black → Rail / humbucker / P90 on-off-on T3 (wire, red)
10. Rail / humbucker / P90 on-off-on T1 → Volume 500k lug3 (wire, black)
11. Volume 500k lug2 → Output jack tip (wire, black)

## What each position does



- Standalone mini-toggles use switchPosition; lever states share the selector index unless noted.
- Passive engine rules not verified (seriesLinkIsolated, requiredTerminalsWired); wiring topology matches the manufacturer diagram.

## Check before plugging in



## Source

Tinkercaster's own drawing of the Seymour Duncan diagram 1PRail\_3mt\_1V, revision 1. Not the manufacturer's artwork and not endorsed by Seymour Duncan.

See also [all wiring diagrams](<https://guitarwiring.app/wiring-diagrams/index.md>).