Not every malfunctioning device necessitates a service call. Mechanical issues are the most common culprits when it comes to problems with home appliances. Components like switches or motors can break or wear out, and loose wires or poor connections can also cause issues that are easily solvable. Any homeowner can acquire the skills to troubleshoot and fix electrical problems with appliances. Keep reading for some easy-to-follow troubleshooting tips!
Editor’s note: Please bear in mind that we do not claim to have final authority on any advice provided here. Before you start working on any wires, make sure to turn off the circuit breaker and use a non-contact voltage tester and/or multimeter to confirm that the power is off. Take all necessary safety precautions to avoid electric shock, and consult with a professional if you are unsure of what you are doing. Electrical matters should not be taken lightly! Also, ensure that you comply with all local and national building and electrical codes.
Most household appliances operate on AC voltage, supplied to your home by the utility company. They use this voltage for heating, lighting, or powering motors, sometimes all at once. However, when a device stops working, troubleshooting electrical problems becomes indispensable. Access to basic tools is essential for this endeavor.
For instance, an Amprobe multimeter is a useful tool that allows you to check if each circuit component is receiving the correct voltage. It can also examine the condition of components and connections. Equipping yourself with these tools can make troubleshooting electrical problems a breeze. To make your life easier, ensure that you have the following tools on hand:
- NCV (Non-Contact Voltage Detector) – This determines if power is flowing to the circuit for your safety.
- Digital Multimeter – This measures AC and DC voltage and can check for continuity (if a wire is open).
- Screwdriver (Phillips and flat head)
- Basic Wire Strippers
- Clamp Meter – This is used to check current draw, but it is more suitable for advanced troubleshooting and repairs.
How to Solve Electrical Problems Step-by-Step
Here’s a recommended step-by-step troubleshooting method you can use to isolate and fix electrical problems near any appliance using a digital multimeter (DMM) and a few basic tools:
1. Check the AC Power Voltage
Believe it or not, some problems can start at the source. Always make sure that your outlet or power supply has the correct AC voltage.
To measure the AC mains voltage at the outlet, set the DMM (Digital Multimeter) function switch to AC Voltage (VAC). Choose a range that is greater than the voltage you wish to measure (greater than 120 volts) if necessary. Autoranging meters automatically select the most appropriate range for you. Next, connect the test leads (red and black) to the voltage (V) and common (C) terminals on the meter.
Using the red multimeter lead, test the “live wire,” and use the black test lead to test the neutral or ground wire. Gently insert the meter’s red probe into the “hot” slot of the socket, which is usually the shorter or narrower slot. Place the black probe in the other vertical or ground slot of the receptacle.
The meter should read between 116 and 124 volts. A device’s power cord is typically terminated with three wires: black, white, and green. Black (or sometimes red) is usually the “live” wire, white is the “neutral” wire, and the green wire should be the ground wire.
Additionally, you should check that there is nearly no voltage between the neutral wire (long slot) and the ground hole.
Low or No Voltage Troubleshooting
If you don’t measure voltage at the outlet, make sure that the circuit breaker or switch controlling the outlet is turned on. Also, ensure that the probes are fully inserted into the sockets. You may need to adjust their angles or move them around to be certain. If you do detect voltage at the outlet, there may be an issue with the power cord, which you should test next.
However, if the measured voltage is much lower than the expected ~120V, there may be a problem with a disconnected neutral (white wire). Since wires usually don’t “break in the middle,” it’s worth checking the neutral wire (white) for corrosion or a disconnection at an outlet or switch on the same circuit. Always turn off the power before inspecting a damaged neutral wire.
2. Check the Power Cord
Over time, the inner conductors of a power cord can break, even if the cord looks fine on the outside. To check the power cord, unplug it from the outlet first. For the next step, you will need access to the internal connections of the device. Never test any wires while the appliance is still connected to an outlet!
Set the multimeter to the resistance or “ohms” function, and measure the resistance between each prong of the plug and the point where the power cord connects to the appliance. The flat narrow blade on the plug should associate with the black wire, the flat wide blade with the white wire, and the round pin with the green wire.
A good power cord should have a resistance of less than 1 ohm from the plug to the end of each wire. Any value above 1 ohm may indicate that the power cord is beginning to fail and could overheat during use. If any wire shows high resistance or displays “OL” on the meter, replace the entire power cord.
3. View Current Draws (for advanced users)
Occasionally, low or high current draw suggests a problem with the motor. Monitoring the current draw can provide clues on how to fix electrical problems when the system isn’t functioning correctly. Current draw can be measured using a clamp accessory connected to a multimeter or a clamp meter. If you’re unsure about what these tools look like, check out our review of the Amprobe clamp meter.
For current measurements, connect the clamp meter accessory or grab the clamp meter. The accessory should be connected to the current jack and the common jack of the multimeter. Clamp the jaws around one conductor (wire) of the circuit you want to measure. Often, you’ll find the power cord splitting off on the appliance side. If you don’t fully understand the risks involved, be cautious or hire an electrician. Be careful not to pinch the jaws on both wires, as this will cancel the signal and show zero current.
Tech Note: The current clamp acts as a step-down transformer, reducing the higher current drawn by the appliance to a much smaller current (typically 1000 to 1) that the DMM can handle.
To measure current with a clamp meter, select the AC current function and place the jaws around a conductor. The display will show the measured current. This step ensures that the device is indeed drawing current. A non-working device may simply be unable to draw any power because it has an internal malfunction.
4. Check the Switch
You can quickly troubleshoot electrical problems by inspecting the onboard switches on small appliances. Ensure that power flows through them correctly to the intended destination. This can be verified using several methods. With the device plugged in, you can check the voltage at both the input and output of the switch.
Insert the probe leads into the voltage and common inputs, and set the meter to AC voltage (VAC) mode. Touch the black probe to the ground (the metal frame of the unit) or to the neutral connector (white wire) on the power cord. Carefully touch the red probe to the switch’s connector, first one side, then the other. With the switch in the “ON” position, there should be voltage present at both the input and output lugs.
Bonus Step: Check Continuity
Another way to test a switch is to check for continuity. To do this, first disconnect the power from the switch by unplugging the unit. Next, isolate the switch by removing the wires from one side of the switch.
Then, with the multimeter set to the Continuity function, place one lead on the switch’s input lug and the other on the switch’s output lug. When the switch is turned on, the multimeter should emit an audible continuity signal and read approximately zero ohms. With the switch in the off position, the sound should stop, and the meter should display “OL”. If this is not the case, you have discovered a problem – a defective switch.
Solving electrical problems with home appliances may seem daunting. However, if the problem is simply a loose cable or a faulty switch, why spend hundreds of dollars on an easy fix? Many electrical problems can be resolved quickly and easily by a homeowner willing to invest a few minutes in basic troubleshooting.
We hope this guide has been helpful to you. We love sharing tips from professional electricians that can assist other professionals who are not experts in the field. If this guide has helped you or if you have additional troubleshooting steps to suggest, please leave a comment below!