The black line wire connects to the common terminal of the first 3 way switch. Connect the ground wire to the green screw.

How To Wire A 3 Way Switch 3 Way Switch Diagram
Three way switch wiring. Connect the wire marked common to the black or dark colored screw. Then a 4 wire cable going between the two 3 way switches and then a 3 wire cable going from the switches to the load. Connect the two remaining traveler wires to the two brass or light colored screws. Three way switch wiring with light middle. When wiring a 3 way switch circuit we will be using a 3 wire cable known as romex coming from the source such as the breaker box. Take your three way switch.
The two hot wires of three wire cable connect to a pair of brass colored traveler terminals on each switch. First bend hook in the ground wire wrap around the green screw. 3 way switch wiring with. If you are trying to troubleshoot a 3 way switch operation then you will need to identify the function of each wire. A 3 wire nm connects the traveler terminals of the first and second 3 way switch together. When wiring a 3 way switch first screw the terminal screws of the new switch until they are difficult to turn.
This might seem intimidating but it does not have to be. This 3 way switch wiring diagram shows how to wire the switches and the light when the power is coming to the light switch. In this diagram the incoming hot wire attaches to the first switchs common dark colored terminal. With these diagrams below it will take the guess work out of wiring. You will see a black screw and two gold screws on the switch. 3 way switch wiring diagram.
In this diagram the electrical source is at the first switch and the. Pick the diagram that is most like the scenario you are in and see if you can wire your switch. Wires consisting of a line a load a neutral a pair of travelers and two 3 way switches. Take a closer look at a 3 way switch wiring diagram. The source in this circuit is at the first switch and the light fixture is. The black screw is the common which we identified in the steps above as the switch leg or hot power source.
All three way switch and 2 way switch wiring diagrams have the same basic components. Typical 3 way switch wiring nm cable in the 1st diagram below a 2 wire nm cable supplies power from the panel to the first switch box. 3 way switch wiring diagrams wiring diagram 3 way switch with light at the end.