Red wire: The second hot/traveler wire is the red wire that serves the same purpose as the black wire between the two switch boxes. Depending on toggle switch configuration, either the red wire or the black wire will be hot if the light is on, but not both.

Where does the red and black wire go on a 3-way switch?

The black hot wire enters the switch on the left. Three-way wire(which includes red, black and white wires) runs from the switch on the left to the switch on the right, with the white wire carrying ground and the red and black wires carrying the output from terminals in the left switch.

What is red wire for in light switch?

What are Red Wires? Red wires are usually used as secondary hot wires. Red wires are also hot and should be clearly marked to avoid the dangers of electrocution. Red wires are commonly used when installing ceiling fans, where the light switch maybe.

What color is common wire in 3-way switch?

black When disconnecting the wires, mark the wire on the black or dark colored screw as common. Mark the wires on the brass or light colored screws as travelers.