Electrical Wiring for Light Fixtures and Three Way Switches

By Dave Rongey - Summary:

How to Wire Three Way Switches: Common Problems When Wiring 3Way Switches, Wiring Connections for 3Way Switches.

Guide to Wiring Connections for 3Way Switches

Electrical Question: We have 2 sets of 3 way switches. One controls the top and bottom of our stairwell, the other controls our kitchen lights.

  • Both seem to have the same problem (making me wonder if its really just a defective switch or something more). In both cases, if you switch on the light on one side, the other will not turn it off.
  • Instead you get a blink and it stays on. You have to turn the light off at the original location. Please note that the top of the stairwell is on a switch plate with 2 others. The 2nd switch goes to another light in the adjacent room (a loft) and is a 2 way. The 3rd has served no purpose since the house was built 8 yrs ago.
  • In addition, I’ve noticed that at times, the kitchen light, even when switched off, stays lit. I have to mess with the switches back and forth a couple times, then I can get it to turn off. This is not consistent.
  • In the kitchen, I’ve at times heard a pop when turning on. From what I’ve read, it can be wires touching, or any number of other things.

I hope this gives you enough information. The reason I haven’t simply changed out switches is because it felt odd that I would have the same problem in 2 different locations in the house.
Any information you can offer would be very much appreciated.

This electrical wiring question came from: Carrie, from Concord, North Carolina.

Dave’s Reply:
Thanks for your electrical wiring question Carrie.

How to Wire Three Way Switches


  • Skill Level: Beginner to Intermediate.
  • Tools Required: Basic Electricians Pouch Hand Tools and Voltage Tester.
  • Estimated Time: Depends on personal level experience and ability to work with tools.
  • Precaution: Identify the light circuit, turn it OFF and  Tag it with a Note before working with the wiring.
  • Notice: Installing additional fixture wiring should be done according to local and national electrical codes with a permit and be inspected.
  • Common Problems When Wiring 3Way Switches
  • From what this question is describing it is possible that there may be an electrical connection problem either at one of the main switch junction boxes or at the electrical panel.
  • When light fixtures stay on even when the switch is OFF may indicated a bad light switch where the set of contacts are stuck together, this is rare but could happen.
  • If the light fixture is switched OFF and the light is dimly lit then this is a problem with the electrical wiring system where there is a problem with a connection or most likely a problem at the electrical panel.
  • I do not recommend homeowners perform any work in their electrical panel.
  • Experienced or qualified electrical contractors will be able to make a few tests and find and correct the problem to avoid further complications.

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Be Careful and Be Safe - Never Work on Energized Circuits!
Consult your Local Building Department about Permits and Inspections for all projects.


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2 Responses to “Electrical Wiring for Light Fixtures and Three Way Switches”
  1. Dave Rongey says:

    Hi Kim,
    If the wiring to the switches has not been altered then it would be best to test the wiring at the light fixture box to identify the connections for the light fixture. The ground wires all connect together as you have described, however the neutral wire of the circuit and the return wire from the three way light switches must be properly identified.
    Please see the Three Way Switch Wiring Diagrams section of this website for additional assistance.
    I hope this helps you,

  2. Kim says:

    I have a three way switch issue. I have two switches that have a four wire line between them. The problem is that there is a three wire line running to the fixture and in the fixture there are three lines meeting there.

    There are two white wires with wire nuts on them individually. The black wires from the two power feeds are nutted with the white from the switch. The black line from the switch is connected to the black wire on the light. All the ground wires are nutted and connected to the white side of the light. How do I attach this to a new light that needs a black, white, and ground wire?


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