RV Electrical Tests

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Electricity powers your camping. If something electrical in your recreational vehicle doesn’t work, you easily can test it with basic tools. Here’s how to test RV electrical systems.

RV Electrical Systems

Our article on RV Electrical Systems described the two sources of electricity in your RV: 12-volt direct current (DC) from a battery and 110-volt alternating current (AC) from “shore power,” the same electrical source as your home. The voltage (power) is different, but the two systems work similarly: electricity is electricity.

Electrical systems are intentionally designed with a weak link, a component that will fail first: fuses or circuit breakers. If an appliance quits, for example, the first step to repairing it is to check for a fuse or circuit breaker. A fuse can be tested for continuity. A circuit breaker automatically turns itself on and only needs to be reset rather than replaced.

The three types of electrical testers for consumers are a continuity tester, a circuit tester, and a multimeter (VOM). All are easy to find and operate, typically coming with printed instructions. You’ll find a variety of electrical test tools at hardware stores, auto parts stores and large discount stores. Shop around and ask for help. You’ll probably keep and use your first electrical test equipment for many years. Here’s how to perform easy electrical tests:

Continuity Tester

Electricity needs a continuous path or circuit to flow. It’s like a two-lane road from point A to point B and back. If one or both lanes are blocked, traffic — in this case, electricity — stops. A continuity tester is useful for checking electrical cords and wires to make sure they can conduct electricity.

To test for continuity, follow these steps:

  1. Disconnect the appliance cord from the power source (electrical receptacle or outlet).
  2. Turn ON any switches on the device.
  3. Attach the alligator clip to one prong of the cord.
  4. Touch the tip of the continuity tester to the other prong. If there is continuity, the tester will light up. If not, it won’t.

Here’s how it works: The continuity tester sends electricity from an internal battery through one cord prong and down the wires. If the continuity tester light gets electrical current from the other prong it illuminates, indicating that the path is complete. Otherwise, something, like a broken wire or component, is stopping it. You can remove the cord from the appliance and test each of the two wires separately to see which one doesn’t work. If both work, the short is in the appliance itself. You can buy a continuity tester under $15.

A circuit tester is simply a continuity tester without an internal battery. It uses the device’s electricity to power it. Be careful using a circuit tester and follow manufacturer’s instructions for safety.


A multimeter (also called a volt-ohmmeter or VOM) is another way of testing continuity. It also can measure the amount of 110-volt alternating current or 12-volt direct current in a plugged-in or live circuit. It can check voltage, too.

For example, a multimeter can verify that there are about 110 volts in an AC circuit or that a 12-volt battery is fully charged. In addition, a multimeter can check resistance. A continuity tester checks resistance, but answers yes or no. A multimeter checks resistance and reports how many ohms (the measurement of resistance) a circuit carries.

Frugal RV Tip

Troubleshooting some devices may not even require that you use a multimeter. Many major appliances have fault codes that you can read and decipher using the owner’s manual. You press a button or two, read the resulting code, and look it up for repair instructions. And, if you don’t have the original owner’s manual nearby, search for it online. Multimeters are relatively inexpensive. The analog unit shown was $10 and the digital multimeter was $20, though you can pay $50 or more for more accurate models.

You can use a multimeter to test motors, electrical outlets, switches, controllers, appliances and many other electrical gadgets. Specific instructions will come with the multimeter you purchase.

Here’s how to use a multimeter to test an electric appliance:

  1. Disconnect the appliance cord from the power source, except when testing a live circuit.
  2. Plug the test leads in to the multimeter.
  3. Select the function (ACV, DVC, resistance) and the range (maximum reading expected).
  4. Connect the probes to the cord or appliance component.
  5. Interpret the reading. Visit our sister website, FixItClub.com, for basic instructions on simple repairs.

>>Dan Ramsey, FrugalRV.com
Travel more – spend less!

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