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Kevin, Licensed Electrical Contractor
Category: Electrical
Satisfied Customers: 3667
Experience:  30 years Licensed Electrical Contractor in Illinois, Adjunct College Electrical Instructor, Former Electrical Inspector, Diploma: Digital Electronics, FCC Technician License
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hi i have a problem. I have 2 white wires and 2 black wires

This answer was rated:

hi i have a problem. I have 2 white wires and 2 black wires a 2 copper wires coming out of the box. i have 1 black 1 white and 1 green on fixture. how do i connect them?

Hello name is XXXXX XXXXX I will be happy to assist you with your electrical question. My goal is to exceed your expectations on Just Answer!


1) Are you trying to connect a wall or ceiling light?


2) What type of switch are you connecting the light to? Is this a single pole switch or a 3-way switch. What are the wire colors on the wall switch and how many wires are connected to the switch?

Customer: replied 4 years ago.

HI Kevin thanks I am connecting a ceiling light. let me look at the switch but i think its a single pole


1) Thanks for the reply Brad............any chance you have a 2-prong AC voltage tester or an AC voltmeter handy to confirm the switched loop wire in the ceiling?
Customer: replied 4 years ago.

the wires are red black and white i have a voltage meter too


1) So the wall switch has 3 wires then, correct? If so, that is a 3-way switch and you will have a quantity of (2) two 3-ways. One of the 3-ways is supplying the hot wire and the other 3-way is supplying the switched loop wire that goes up to the ceiling. Each of the 3-ways will have 1 black screw terminal and 2 brass screws. You will need to determine which of the 3-ways connects to the ceiling. One of the switches that has the black screw terminal will be the connecting switched loop wire going to the ceiling. The other 3-way that has the black screw terminal will be the hot circuit feed originating from the circuit breaker.

2) Turn the breaker to the OFF position. Spread apart the hot and white neutral and copper ground wire in the ceiling. Turn the breaker back to ON. At the ceiling, measure for 120 volts with the meter by touching 1 probe to the hot and the other probe of the meter to either the white neutral or the bare copper. By controlling the switch to ON/OFF, you should alternately measure 120 volts when the switch is ON and 0 volts when the switch is OFF.


3) Refer to the attached diagram to assist you. The hot wire of the light fixture will connect to the switched loop ceiling hot wire and the white neutral of the fixture will connect to the ceiling white neutral. The fixture green wire will connect to the ceiling bare copper ground wire.





Let me know how you make out and we can take it from there..........Thanks.........Kevin!

Kevin and 5 other Electrical Specialists are ready to help you

1) To determine which of the 3-ways is the hot feed and which 3-way is the switched loop going to the ceiling, you can measure voltage at the black screw of each 3-way with 1 probe on the black screw and the 2nd probe on a bare copper ground wire. If you constantly get 120 volts at the black screw on 1 switch, that switch is the hot supply. If you alternately measure 120 volts at the black screw by turning the switch ON/OFF, that switch will be the switched loop connection going up to the ceiling.


Refer to the diagram and you will see what I mean.


2) No need to remove any wires on either of the switches. Just temporarily back them out of the box so you can have access to the black screw terminal and a bare copper ground wire in the box.



Brad..........Thank you for the excellent service rating.............much appreciated!


If you have any other questions, just let me know.


Take care and have a safe and Happy 4th of July............Thanks............Kevin!