How to Read and Use a Wiring Diagram for DIY Appliance Repair

By Lyle Weischwill | Feb. 02, 2023 11:52 am PST

Knowing how to read and use an appliance’s wiring diagram helps make sure you buy the right part to complete DIY repairs when something goes wrong with the appliance.

Reading a wiring diagram can feel overwhelming—like a foreign language. But you can learn and understand the basics of using a wiring diagram by studying the following 3 sections of wiring diagram training. Videos in each section will help you become an expert at using a wiring diagram in no time.

Warning: When completing DIY appliance diagnosis and repair, ALWAYS unplug the appliance before accessing internal components and making checks or repairs.

1. Decipher the Symbols Used in Wiring Diagrams

First, we’ll take a look at some of the most common symbols you’ll find in a wiring diagram and learn what they mean.

  • Lines. The lines are wires. They connect the symbols, which represent components of the appliance. Following the lines will help you determine, the cause of a failure and buy the right part to fix the problem.

  • Switches. Most appliances have switches. The symbol for a switch on a wiring diagram looks like this: __/ __ . The switch starts and stops current going to a circuit or component in the appliance.

  • Dots. Dots on a wiring diagram signify wiring connections to switches and components.

Learn more about the basic symbols you’ll find on a wiring diagram (also called a wiring schematic) by viewing this short video.

Many wiring diagrams have the symbols labeled, or they have a symbol key on the diagram to help you decipher the symbols.

Here are a few more examples of common symbols you’ll see on appliance wiring diagrams.

Appliance wiring diagram symbols

2. Learn How to Read a Wiring Diagram

Once you understand the symbols used, you can learn how to read a wiring diagram or schematic.

This video explains where to locate a wiring diagram for an appliance and how to read it.

Learning to trace wires through components on a wiring diagram will help you understand what’s keeping a part from working in your appliance.

3. Trace a Circuit to Diagnose an Alliance Failure

Electric current travels in a loop called a circuit. A wiring diagram shows a map of the wires that connect all of the circuits in an appliance.

When a component fails, you can trace the circuit through that component to know what to physically check to diagnose the failure.

View this video to see an example of tracing a circuit and diagnosing a component failure in a refrigerator.

As shown in the video, you’ll need a multimeter to check wiring and components in an appliance when diagnosing a failure. Our How to use a multimeter to test electrical parts video shows you how.

Multimeter for diagnosing appliance failures

Accurately diagnosing a failure using a wiring diagram and multimeter will help you buy the right part so you can get the appliance working again.

Circuits in appliances can be more complicated than the one shown in the above video, but you can use this basic method of tracing and testing a circuit to understand possible causes of failures in your appliances.

When working on your appliances, always heed this warning:

Undertaking repairs or maintenance to appliances or power equipment can be hazardous. Should you choose to undertake repairs or maintenance, you are assuming the risk of injury to your person or property. In an effort to reduce the risk, use the proper tools and safety equipment noted in the applicable guide and follow all instructions. Always UNPLUG the appliance or disconnect electrical power by shutting off the house circuit breaker before beginning diagnosis and/or repair. Do not proceed until you are confident that you understand all of the steps and are capable of completing the repair. Some repairs or maintenance, however, should only be performed by a qualified technician.

Schedule in-home service by a Sears Technician when you encounter an appliance failure that you can’t fix yourself. Sears Technicians perform more than 7 million repairs annually and we have thousands of appliance experts employed nationwide. Sears is the #1 appliance repair service in the country, delivering guaranteed quality and workmanship.

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