The two traveler wires from one end of the circuit go to one pair of terminals on the 4‑way switch, and the two traveler wires from the other end go to the opposite pair. The order within each pair generally does not matter.
Understanding the 4‑Way Switch
A 4‑way switch sits between two 3‑way switches in a multi‑location lighting circuit. It has four terminals arranged as two pairs on opposite sides. It does not have a common terminal; instead it passes or cross‑connects traveler conductors from the far ends depending on the switch position. The two traveler wires coming from the first 3‑way must stay on one side’s pair, while the two travelers from the second 3‑way go to the opposite side’s pair.
Wiring It Correctly: Where to Put the Wires
Before you begin wiring, identify which wires go to each end of the circuit. Two of them originate from one 3‑way switch, the other two from the other 3‑way. The following steps assume a standard four‑terminal 4‑way device with two terminals on each side.
To wire it, follow these steps:
- Turn off power at the breaker panel and verify that the circuit is dead with a tester.
- Identify the traveler pairs coming from each end of the circuit. Generally, you’ll see two wires from one side and two from the other; common colors are red and white or red and black. If a white wire is used as a traveler, mark it with colored tape to show it is hot.
- Remove the 4‑way switch and note which two wires come from each end. Do not separate the pairs; keep each end together.
- Connect the two wires from one end to one side of the 4‑way (the two terminals on that side). Connect the two wires from the other end to the opposite side. The specific terminal order within each pair is not critical on most switches.
- Attach the ground wire to the switch’s green grounding screw if present, and restore the neutral path if needed (neutrals should remain spliced in the box and not connect to the 4‑way).
- Reinstall the switch plate, restore power, and test the circuit from both 3‑way locations to ensure proper operation in both positions of the 4‑way.
With the wiring complete, the light should be controllable from all three switch locations—two 3‑ways and the 4‑way—depending on the position of the switches.
Tips and Safety Considerations
Keep safety in mind and follow local electrical codes. The following tips help prevent common mistakes and hazards.
- Always turn off power at the breaker and verify with a tester before touching wires.
- Do not mix neutrals with the 4‑way switch. Neutrals should remain tied together in the box and bypass the switch.
- Ground the switch if it has a grounding screw; connect to the equipment grounding conductor.
- Label wires or take a photo before disconnecting anything so you can reassemble correctly.
- If you’re uncertain about which wires are which, or if your circuit uses unusual conductor colors, consult an electrician.
Replacing a 4‑way switch with one that has the same terminal layout is advisable for ease of wiring. If you encounter nonstandard terminals, refer to the manufacturer’s wiring diagram.
Summary
A 4‑way switch has two pairs of traveler terminals. Connect the two traveler wires from one end of the run to one side of the switch and the two traveler wires from the other end to the opposite side. The order within each pair generally doesn’t matter, and ensure neutrals stay spliced and the ground is solid. With power restored, the light should be controllable from all three switch locations—two 3‑ways and the 4‑way—depending on the switch’s position.