How do you wire a 4 way switch?

Put the 4-way switch between two 3-way switches. Connect the two travelers from the first 3-way switch to one pair of terminals on the 4-way switch and the two travelers to the second 3-way switch to the other pair. The supply hot goes to the common of one 3-way switch and the light hot to the common of the other. The neutral bypasses every switch and all grounds are joined.

Which terminals are the pairs on a 4 way switch?

On most 4-way switches the pairs are told apart by screw color, two brass and two black. Pairs are usually told apart by screw color; some makers use other markings. Do not go by position alone. Read the instructions that come with the switch.

Does a 4 way switch have a common terminal?

No. A 4-way switch has four traveler terminals and a ground screw. The common terminals are on the two 3-way switches at the ends of the run.

How do I wire a 4 way switch with the power at the light?

Run the supply to the light box, send the hot on re-marked white conductors through the first two switch boxes to the common of the far 3-way switch, and bring a black wire back from the common of the near 3-way switch to the fixture. The travelers run between the switches as usual. The second diagram shows it. New work in many areas needs a neutral at lighting switch locations (NEC 404.2(C), with exceptions), and this layout has none, so check local rules first.

Why does my 4 way switch only work in one position?

Usually one traveler from a 3-way switch is on the wrong pair of the 4-way switch. Turn the power off and check that each 3-way switch has both of its travelers on the same pair.

How many 4 way switches can I add?

As many as you need, one per extra location, all wired in the traveler run between the two 3-way switches. Each 4-way switch takes travelers in on one pair and sends them out on the other.

Can I rely on an AI-generated 4 way switch diagram?

No. Treat it as a picture. Image models often draw wrong connections, for example a split traveler pair or a neutral through a switch. Check every AI picture against the exact diagrams on this page.

Is the 4 way switch wiring diagram generator free?

Reading the exact diagrams and the table on this page is free. The AI illustration tool starts free with 2 image credits, valid for 7 days, no card required. Image credit packs start at $4.99 (Lite, 8 image credits), and the credits do not expire.

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4 Way Switch Wiring Diagram Generator for Three Switch Locations

Exact 4-way switch wiring diagrams for three switch locations: power at the first switch or at the light, traveler pairs marked. Planning drawings only.

Exact diagrams: power at the switch and power at the lightTraveler pairs of the 4-way switch markedConnection table built from the same list the checker usesAI illustration tool for your own lighting circuit

Planning diagrams, not code advice. Turn the breaker off and test for voltage before you open a box. Follow local code and the device instructions, and a licensed electrician decides what gets installed.

Controlling a light from only two places? You need two 3-way switches and no 4-way switch: for two switch locations, see the Three Way Switch Wiring Diagram Generator.

4 Way Switch Wiring Diagrams

Exact diagrams drawn in code from a connection list checked against public sources (Purdue 4-H, NEC text). Each shows the supply, the two 3-way switches with their commons, the 4-way switch with its two traveler pairs, the light, the neutral, the ground and the cable runs. One light, three switches, 120 V.

Exact wiring diagram of a 120 V four-way switch circuit: breaker hot to the common of 3-way switch S1, two travelers in 14/3 cable to the IN pair of 4-way switch S4, two travelers from the OUT pair of S4 to 3-way switch S2, the common of S2 to the light, neutral spliced through every switch box to the light, ground chained to every device — Power at the first 3-way switch, light at the end of the run
The supply cable enters the box of S1. The hot goes to the common of S1. Its two travelers go to one pair of terminals on the 4-way switch, and the other pair sends two travelers on to S2. The common of S2 carries the switched hot to the light. The neutral passes through all three switch boxes without touching a switch.
Cable runs: 14/2 from the panel to S1, 14/3 from S1 to S4, 14/3 from S4 to S2, 14/2 from S2 to the light.
Known simplification: the neutral is drawn as one wire from the panel to the light. In the boxes it is spliced through every switch box with a wire nut. The 4-way switch is drawn in the straight-through position; the crossed position is dashed.

Exact wiring diagram of a 120 V four-way switch circuit with power at the light: supply hot spliced in the light box to a white conductor re-marked black, carried through splices in the S1 and S4 boxes to the common of 3-way switch S2, travelers from S2 to the OUT pair of 4-way switch S4 and from the IN pair to S1, black return from the common of S1 to the light, neutral only in the light box — Power at the light, three switches beyond it
The supply cable enters the light box. The black hot is spliced there to the white conductor of the 14/2 cable to S1, and carried on the white conductors of the two 14/3 cables through the S1 and S4 boxes to the common of S2. Every one of those whites is re-marked black at each end and carries the supply only. The common of S1 returns on the black conductor to the light. The neutral stays in the light box.
Cable runs: 14/2 from the panel to the light box, 14/2 from the light box to S1, 14/3 from S1 to S4, 14/3 from S4 to S2.
Known simplification: the neutral is drawn as one wire from the panel to the light box. The re-marked whites are drawn with black bands. This layout has no neutral in any switch box. New work in many areas needs a neutral at lighting switch locations (NEC 404.2(C), with exceptions), so check whether this layout is allowed for new work where you live.

Connection Table: Commons, Traveler Pairs, Neutral, Ground

The same connections as the diagrams. Every terminal appears once. Within one pair, the two travelers may be swapped; a traveler may not move to the other pair.

Layout	Connected together
power at the first 3-way switch	Supply hot + 3-way S1 common 3-way S2 common + Light hot Supply neutral + Light neutral Supply ground + 3-way S1 ground screw + 4-way S4 ground screw + 3-way S2 ground screw + Light ground 3-way S1 travelers T1 and T2 to the IN pair of 4-way S4 (IN 1 and IN 2, one traveler each) 4-way S4 OUT pair (OUT 1 and OUT 2) to 3-way S2 travelers T1 and T2 (one traveler each)
power at the light (white conductors re-marked as the supply)	Supply hot + 3-way S2 common 3-way S1 common + Light hot Supply neutral + Light neutral Supply ground + 3-way S1 ground screw + 4-way S4 ground screw + 3-way S2 ground screw + Light ground 3-way S1 travelers T1 and T2 to the IN pair of 4-way S4 (IN 1 and IN 2, one traveler each) 4-way S4 OUT pair (OUT 1 and OUT 2) to 3-way S2 travelers T1 and T2 (one traveler each)

Colors are insulation colors in NM cable, not phases. IN and OUT are names for the two pairs; your switch may mark them by screw color or as LINE and LOAD, and its markings win.

This page covers one light and three switches. For two switch locations, see the Three Way Switch Wiring Diagram Generator. For other wiring, such as home, automotive, or appliance systems, use the Wiring Diagram Maker.

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Exact wiring diagram of a 120 V four-way switch circuit: hot to the common of S1, travelers through the 4-way switch S4 to S2, the common of S2 to the light

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AI diagrams are drafts. Check every common, traveler pair, neutral and ground against the exact diagrams.

Sources (checked October 2026): Purdue Extension 4-H, Wiring Diagrams for 3-Way and 4-Way Switch Combinations, Eaton, How to wire an Eaton 4-way switch, NFPA, NEC Code-Making Panel 5 draft (200.7(C)(1), numbered 200.8(C)(1) in the 2026 draft), Mike Holt, Switches, based on the 2020 NEC (404.2), and the Leviton 4-way switch instruction sheets for the terminal layout.

What a 4 way switch wiring diagram shows

A 4 way switch wiring diagram shows how one light is controlled from three places. The two ends of the run are 3-way switches, and the 4-way switch sits between them in the traveler wires. A 4-way switch has four traveler terminals in two pairs and no common. In one position it passes the two travelers straight through, in the other it crosses them. Flipping any of the three switches changes which path is live, so the light turns on or off from every location. This page draws two layouts as exact diagrams from a documented connection list checked against public sources (Purdue 4-H, NEC text) and puts the same connections in a table.

Two switch locations or three?

For a light controlled from two places you do not need a 4-way switch at all: use two 3-way switches. The Three Way Switch Wiring Diagram Generator linked below covers that circuit, including the power at the light layout.
For three locations, add one 4-way switch between the two 3-ways. For four locations, add a second 4-way switch in the traveler run: each 4-way switch repeats the same pattern, travelers in on one pair and out on the other. The two ends are always 3-way switches.

The two pairs: where most 4-way wiring goes wrong

The two travelers from one 3-way switch must land on the same pair of the 4-way switch, and the two travelers to the other 3-way switch on the other pair. Eaton tells installers to connect each set of travelers to the two screws of the same color, and Leviton describes the 4-way switch as two pairs of traveler terminals. Some devices pair the screws top and bottom or print LINE and LOAD instead, so the instructions of your switch decide.
If one traveler from S1 lands on the IN pair and the other on the OUT pair, the circuit still lights in some positions, which makes the fault confusing: the 4-way switch then works only in one position, or one of the end switches stops working. A checker compares each drawing on this page with the reference layout and rejects a drawing with a split pair, a traveler on a common, or a neutral through a switch.
Swapping the two travelers inside one pair is harmless, because they are interchangeable. Moving a traveler to the other pair is not.

Power at the switch or power at the light

Open the boxes and find where the cable from the panel arrives. If it arrives in the box of an end switch, use the first diagram. If it arrives in the light box and the cable to the switches starts there, use the second.
Not covered on this page: a light between the switches, several lights on one circuit, dimmers and smart switches. Use the Wiring Diagram Maker below for a rough draft of those, and have the layout checked.

The white wire that is not a neutral

In the power at the light layout the supply has to travel to the far switch on the white conductor of each cable, because 14/2 and 14/3 cable have no other conductor to spare. NEC 200.7(C)(1) (2017 to 2023 numbering; the 2026 draft renumbers it 200.8(C)(1)) allows a white conductor in a cable to be used as a hot only if it is permanently re-identified at each termination and wherever it is visible and accessible. For single-pole, 3-way and 4-way switch loops the re-identified conductor may be used only for the supply to the switch, not as the return conductor from the switch to the outlet. The quoted wording is from NFPA's Code-Making Panel 5 draft for the 2026 NEC; check the edition your area has adopted.
In the diagram the re-marked whites carry only the supply to S2, and the black conductor is the return from S1 to the light. The travelers stay on black and red.

Neutral at the switch boxes

The switching is done on the hot conductor only (NEC 404.2(A)), so the neutral never lands on a switch in either diagram. Separately, since the 2011 edition the code asks for a neutral at many lighting switch locations (404.2(C)), with exceptions; where several 3-way and 4-way switches control the same lights and are visible in one room, a neutral is needed at only one of them (as summarized by Mike Holt for the 2020 NEC). This matters for smart switches and for new work. Ask your local inspector or a licensed electrician what applies where you live.

Troubleshooting a 4-way circuit

The light works from the two end switches but the middle switch does nothing: both traveler pairs are probably on the same pair of 4-way terminals, or the 4-way switch is bypassed.
The middle switch works in one position only, or an end switch stops working when the middle switch is flipped: a traveler pair is split across the two pairs of the 4-way switch.
The light never turns on: the supply is not on a 3-way common, the light wire is not on the other common, or a splice is loose.
The breaker trips when you turn the power on: a hot touches a neutral or a ground, or a traveler is joined to a common. Turn the power off and check every splice.

Before you open a box

Turn the breaker off and test every wire for voltage. A switch box can hold wires from another circuit.
Check how the boxes are wired before you copy a diagram. Many existing circuits do not match a textbook layout.
The diagrams show 14 AWG cable on a 15 A breaker. Use 12 AWG cable on a 20 A circuit, and match the cable, breaker and switch rating together.
After wiring, test the light by flipping each of the three switches on its own, in every combination.

Exact diagrams vs AI drafts

The two diagrams above are exact reference diagrams. They are drawn in code from a documented connection list checked against public sources (Purdue 4-H, NEC text), and a checker compares each drawing with a reference table. We do not show AI-generated wiring images as examples, because image models often draw wrong connections, such as a split traveler pair or a switched neutral. The generator on this page still produces an AI illustration from your prompt. Treat it as a rough picture, compare it with the exact diagrams, and let a licensed electrician decide what gets installed. A diagram from this page is a planning picture, not a permit drawing, and it does not replace the device instructions or the electrical code that applies in your area.