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Light Switch Wiring Troubleshooting

Wiring a Light Switch – The types of Circuit Wires Typically Found in a Switch Box and How They are Connected, To Get Your Light Switches Working it is helpful to understanding that a light switch is basically the switching of a the power source as explained here with the help of Wiring Diagrams for Light Switches.


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How Wire a Light Switch

Light Switch Wiring Explained
Electrical Question:  I am confused about the wiring of  a light switch.

Received from Gilbert a Handyman in Sacramento, Calif.

Dave’s Reply:
Thanks for your electrical question.

How to Wire Light Switches

Application: Wiring a Light Switch.
Skill Level: Beginner to Intermediate, best performed by a licensed electrician.
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 lighting circuit, turn it OFF and  Tag it with a Note before working with the wiring.
Notice: Installing additional electrical wiring for light fixtures should be done with a permit and be inspected.

Identifying the Circuit Wiring
It is very helpful to identify the wires and then organize them together into groups so you understand which wires will be spliced together and which wires will be attached to light switch.

Types of Circuit Wires Typically Found in a Switch Box and How They are Connected

Grouping the Wires Together

Once the wires have been identified, then the wires can be organized into groups that will be spliced together to keep the circuit connections, and the additional wires that will be necessary to connect the circuit power to the light switch.

The Power In and Power Out black wires are spliced together, and an additional wire is added to provide power to the switch. The Black wire that goes to the light fixture is attached to the light switch. All the White Neutral wires are spliced together. All the ground wires are spliced together and bonded to the switch and box. Note: Some switch boxes may have more than one electrical circuit cable, and these wires must be identified as well so they can be kept separate from the light fixture circuit wiring.

For More Complex Wiring for Light Switches
To Get Your Light Switches Working it is helpful to understanding that a light switch is basically the switching of a the power source as explained here with the help of Wiring Diagrams for Light Switches

How to Troubleshoot a Light Switch Wiring Problem
Troubleshooting electrical wiring begins with identifying the problem, asking a lot of questions, then start the process of elimination. Work the problem backwards starting with what does not work and travel back towards the source until you find the problem.

See More about Wiring Light Switches

Wiring Diagrams

Electrical Wiring Diagrams

Home electrical wiring diagrams are an important tool for completing your electrical projects. An electrical wiring diagram can be as simple as a diagram showing how to install a new switch in your hallway, or as complex as the complete electrical blueprint for your new home or home improvement project.

How to Wire a Light Switch
Troubleshooting Electrical Wiring

The following may also be helpful for you:

Dave's Guide to Home Electrical Wiring:

» You Can Avoid Costly Mistakes! «

Here's How to Do It:
Wire It Right with the help of my Illustrated Wiring Book

Great for any Home Wiring Project.
  electrical wiring  

Complete Guide to Home Electrical Wiring

Perfect for Homeowners, Students,
Handyman, Handy Women, and Electricians
Wiring GFCI Outlets
Wiring Home Electric Circuits
120 Volt and 240 Volt Outlet Circuits
Wiring Light Switches
Wiring 3-Wire and 4-Wire Electric Range
Wiring 3-Wire and 4-Wire Dryer Cord and Dryer Outlet
How to Troubleshoot and Repair Electrical Wiring
Wiring Methods for Upgrading Electrical Wiring
NEC Codes for Home Electrical Wiring
....and much more.

Learn more about Home Electrical Wiring
with my Online Video Course:
Basic Home Electrical Wiring by Example

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

Electrical Tips to Help You Wire it Right

The Safest Way to Test Electrical Devices and Identify Electric Wires!

The Non-Contact Electrical Tester
This is a testing tool that I have had in my personal electrical tool pouch for years, and is the first test tool I grab to help identify electrical wiring. It is a Non-contact tester that I use to easily Detect Voltage in Cables, Cords, Circuit Breakers, Lighting Fixtures, Switches, Outlets and Wires. Simply insert the end of the tester into an outlet, lamp socket, or hold the end of the tester against the wire you wish to test. Very handy and easy to use.

The Quickest Way to Check for Faulty Electrical Wiring!

The Plug-In Outlet Tester
This is the first tool I grab to troubleshoot a problem with outlet circuit wiring. This popular tester is also used by most inspectors to test for power and check the polarity of circuit wiring.
It detects probable improper wiring conditions in standard 110-125 VAC outlets Provides 6 probable wiring conditions that are quick and easy to read for ultimate efficiency Lights indicate if wiring is correct and indicator light chart is included Tests standard 3-wire outlets UL Listed Light indicates if wiring is incorrect Very handy and easy to use.

Strip Off Wire Insulation without Nicking and Damaging the Electric Wire!

The Wire Stripper and Wire Cutter
My absolute favorite wire stripping tool that I have had in my personal electrical tool pouch for years, and this is the tool I use to safely strip electrical wires.
This handy tool has multiple uses:
The wire gauges are shown on the side of the tool so you know which slot to use for stripping insulation.
The end of the tool can be used to grip and bend wire which is handy for attaching wire onto the screw terminals of switches and outlets..

The wire stripper will work on both solid and stranded wire. This tool is Very Handy and Easy to Use.

More articles about Light Switch Wiring and Home Electrical Wiring:
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How to Wire a Dryer Outlet Help for Bathroom Light Circuit Problems

FAQs Frequently Asked Questions and Comments

2 Responses to “Light Switch Wiring Troubleshooting”
  1. Dave Rongey says:

    Wayne, the incoming power should be the primary power for the switches and the line connection for the gfi outlet. Basically your attaching three pigtails to the power source for these three devices. The neutral is shared for the light, the fan and the line side of the gfi outlet.

  2. wayne says:

    I would like to install the following switches for, a bathroom ceiling fan, a bathroom light fixture, and a GFI receptacle, all in a 3 gang box. I have the power supply now in a junction box that was for the existing ceiling fan that I can access.

    How do I wire the existing fan, and light with the gang box switches and GFI

    Thank you for the help.