A 3-way switch light is a very common system in all homes and they are used to operate 2 switches for one specific light. Although there are several methods for wiring a 3-way switch, there is one which is the most common of all.
On a number 14/2 wire bring the power supply in to either the hot switch box or the neutral switch box and then run number 14/3 wire to the other switch location. Run a number 14/2 wire up to the light box from the second switch.
Join the white wire from the power supply to the white wire in the 3 wire cable going towards the other switch, in the first box. Then connect the black wire on the screw of the 3 way switch. The two remaining screws on the switch are connected with the red and black conductors from the number 14/3 cable.
The white wire going up towards the light will be connected with the white wire from number 14/3 cable, on the switch's other location. Where as the red and black conductors from the number 14/3 cable will be joined to the same screws as on the other 3-way switch and the black wire going towards the light will be tied on the common screw.
On a number 14/2 wire bring the power supply in to either the hot switch box or the neutral switch box and then run number 14/3 wire to the other switch location. Run a number 14/2 wire up to the light box from the second switch.
Join the white wire from the power supply to the white wire in the 3 wire cable going towards the other switch, in the first box. Then connect the black wire on the screw of the 3 way switch. The two remaining screws on the switch are connected with the red and black conductors from the number 14/3 cable.
The white wire going up towards the light will be connected with the white wire from number 14/3 cable, on the switch's other location. Where as the red and black conductors from the number 14/3 cable will be joined to the same screws as on the other 3-way switch and the black wire going towards the light will be tied on the common screw.
