How To Splice Wires (DIY)

Introduction

Every homeowner or DIYer should know how to splice wires safely. Maybe you're thinking about putting in a new light fixture, or changing an old receptacle to a USB-charger receptacle. The safety of your project depends on every splice you make.

Electricity is delivered to lights and receptacles from your electrical panel via wires in the walls and ceiling. At each outlet, the wires must be attached to the new device and to the wires continuing through the walls to the next outlet.

The point where the wires join together is called a splice. Splices must be safe and secure. Loose wires cause arcing and sparking, which can start a fire or shock someone.

Always turn off the power at the circuit breaker in the electrical panel before doing any electrical work. Use a multimeter or non-contact voltage tester to test every wire in the outlet box before starting your project. Turn off the main breaker if it makes you more comfortable.

Here I'll show you two ways to make a splice. Using a wire nut is the traditional method, but push-in connectors are popular and easy to use, too. Push-in connectors come in handy when there's not much wire length in the box to work with.

Most homes built today are wired with non-metallic sheathed cable (Romex is a popular brand), so that's what I'm using in these photos.

A clarification about cost: if you're not buying wire, it's less than $10 for the connectors. If you're wiring to a new location, it's about $20 to $25 for 15 feet of Romex, and less than $5 for a cut-in junction box. Switches and receptacles can range from less than a dollar (for a simple snap switch) to more than $20 for a USB-charger receptacle.If you have to buy tools, add an additional $60.