Wiring 3 Way and 4 Way Switches with Multiple Lights
–Check local regulations for restrictions and permit requirements before beginning electrical work– The user of this information is responsible for following all applicable regulations and best practices when performing electrical work. If the user is unable to perform electrical work themselves, a qualified electrician should be consulted.
The diagrams on this page illustrate connecting multiple lights in 3 way and 4 way switch circuits. Check below for more details about these circuits and some troubleshooting tips.
Wiring a 3 Way Switch with Multiple Lights
In this circuit, two light fixtures are shown but more can be added by duplicating the wiring arrangement between the fixtures for each additional light. Here the source is at the first switch, SW1, and 3-wire cable runs from there to the first light, L1. Two, 2-wire cables run between each light fixture after that and 3-wire cable runs from the last light to SW2.
At the beginning of the circuit the hot source is connected to the common terminal on SW1. The neutral is spliced to the white cable wire running to the lights and then spliced with a pigtail to the neutral terminal at L1. It is also spliced with the white wire running to the second light, L2. At L2 this white wire connects directly to the neutral terminal on the light fixture. If more lights are added, this wire would be spliced to the fixture and to the white wire running to the next light.
The travelers are run between the lights using the second cable black and white wires and at the last light, they are spliced to continue on to the traveler terminals on SW2. They don't connect to the light fixtures at any point. The white traveler wire is wrapped with black tape to mark it as hot
Wiring 2 Lights and 3 Way Switches
This diagram illustrates another multiple light circuit controlled by 3 way switches. Here the source and the fixtures come before the switches. As with the other diagrams on this page, more lights can be added by duplicating the wiring arrangement between the fixtures.
A 3-wire cable runs from L1 to L2 and 2-wire cable runs from there to the first switch. A 3-wire cable runs between SW1 and SW2. The source hot is spliced to the black wire running between the lights and at the last light it is spliced to the black wire running through to the common on SW1, it does not connect to the light fixtures. The white wire is marked with black tape and spliced to the black wire running to the common terminal on SW2.
Back at the lights the source neutral is connected to the neutral terminal on L1 and spliced with the white wire running to the next fixture. At each light it's connected to the neutral terminal with a pigtail and at the last light, directly to the fixture neutral. At SW1 the red and white wires from the 3-wire cable running between the switches function as the travelers with the white marked for hot using black tape or paint.
Wiring 3 Switches and 2 Lights
This drawing shows the wiring for multiple lights in a 4 way switch circuit with the source and fixtures coming before the switches. More lights can be added to this circuit by duplicating the wiring shown here for each additional fixture. Here 3-wire cable runs between L1 and L2, 2-wire cable runs from the last light to SW1, and more 3-wire cable runs from SW1 to the 4 way switch and then to SW2.
At the lights the hot source is spliced to the black wire running between lights, it does not connect to the lights. At the last fixture it is spliced to the black wire running to the common on SW1. The neutral from the source is connected to each light fixture with a pigtail and to the neutral running to the next light. At the last light the source neutral is connected directly to the fixture neutral terminal.
The red wire between the lights is connected directly to the hot on L1 and then run to the next light. If there are more than 2 lights, the red is pigtailed to the fixture hot and to the red wire running on to the next light. With 2 lights, it is spliced with the white wire running to the switches. This white wire is wrapped with black tape to mark it as hot.
At SW1 this marked white wire is spliced to the marked white running to the 4 way switch and at the 4 way, it is spliced again to the marked white wire running directly to the common terminal on SW2. This white wire does not connect to the 4 way switch.
The black and red wires running between the switches serve as the travelers for the circuit. At the 4 way the travelers from SW1 connect to the two terminals at T1. The two terminals at T2 connect to the black and red travelers running to SW2.
About 3 Way and 4 Way Switch Circuits
A 4 way switch must be wired between two 3 ways as shown in the diagrams on this page. A 4 way has five connections: one ground, and 4 circuit terminals divided into two matching pairs. Each pair of terminals should be wired to the traveler wires from one of the 3 way switches. The travelers can be wired to either terminal in a pair, but don't mix up the pairs or the circuit won't work properly.
Three-way switches have 3 terminals to carry circuit electricity and one terminal for a ground wire. Of the three circuit terminals, one is called the common and the other two are known as travelers. The common terminal may be labeled and is usually a different color than the traveler terminals. Depending on the manufacturer, the travelers may be on opposite sides of the device or the two terminals may be on the same side. In any case, the common terminal will be distinguished from the travelers in some way.
The common terminals will always be connected to a hot wire, either from the source or on the light fixture. These connections can be reversed if it's more convenient, as long as one of the 3 way common terminals connects to the hot source and the other one connects to the hot on the load, these circuits will work properly. The traveler terminals will always be connected from switch to switch. Travelers never connect to a device load or to a source wire. It doesn't matter which traveler terminal is used for which traveler wire, reversing them should make no difference.
Troubleshooting 3 Way Switch Circuits
If your switches stop working they may be worn out or the screws may have come loose. If you've wired a new switch correctly and the circuit still doesn't work, the switch may be defective. Check that all connections are tight. Check the switch, remove it from the circuit and test for failure with a continuity tester or multimeter set on the Ohms setting.
If the switch is good and things still don't work, check the wiring to be sure the hot source is connected to a common terminal and the light fixture hot is connected to a common terminal. Likewise, be sure the traveler terminals are connected between switches only and not to any hot wires or the load. Also be sure the neutral from the source is connected to the neutral terminal at the light. A neutral wire will not be connected to the switches in these circuits, although some smart switches may make use of a neutral wire to operate the device.