RV And Camper Trailer Electrical Repair : Choosing And Using A Digital Multimeter
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Why A Multimeter Is An Essential RV Tool
Unlike your home, your RV or camper trailer experiences quite a bit of jostling and bouncing over the course of the camping season. This movement can cause the electrical connections to become loose as they vibrate during transit. Common problems, such as you have in your home, are multiplied but are solved in much the same manner.
For the veteran camper, one of the most important and useful tools to have on board is a good electrical multimeter. While a simple test lamp may be utilized to solve simple electrical problems, a well made electrical multimeter can be used to test for breaks in the wiring or in malfunctioning circuit breakers. But just having a good electrical testing multimeter is not enough. You have to be able to use the multimeter correctly.
On The Road Again?
Which Multimeter Should You Choose?
Just deciding which multimeter to purchase can be difficult because of the many brands and price ranges of electrical test meters offered online and in the stores. But even a low priced multimeter will handle most electrical testing problems you will likely encounter in your RV. The better models of electrical test meters are naturally better made for durability and long life.
No matter which multimeter you choose, be sure the test leads (wires with probes) are long enough and are of good insulation. The better multimeters have good electrical test leads. So don’t scrimp on the cost, you are going to be holding these leads in your hands!
Setting Up The Multimeter
Once you’ve made your choice, it is now time to learn how to use a multimeter. It may seem confusing at first, but there are not that many different settings and probe positions used for most electrical testing procedures. Install batteries as per the multimeter instructions which should come with the electrical test meter.
Because of the many different models of multimeter, it is necessary to determine the correct inputs for the electrical test probes. Some models of multimeters require the electrical testing probes be in different inputs for continuity or voltage testing.
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Using The Multimeter For Continuity Testing
Of the two most common causes for RV electrical problems, breaks in wiring tend to be the hardest to solve. Using a multimeter makes finding the problem much easier. As per multimeter instructions, plug the electrical test probes into the proper holes and set the multimeter for OHMS. The particular wires or circuits to be tested must be turned off at the breaker box before being tested.
The multimeter uses a weak electrical current which will flow from one probe through the wire or circuit, and into the other probe if no breaks exist. The multimeter instructions will indicate the proper digital reading for an open loop OL or random numbers. When the circuit is closed the multimeter display should read 000.
Test the meter by touching the tips of the electrical testing probes together. The digital display should read 000. Some mutimeters give off an audible beep which allows the user to watch the probes instead of the display. This setting can be used for electric water heaters to ascertain continuity in the heating element. Any suspected break can be tested in this manner.
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Using The Multimeter For Voltage Testing
Many Rvs and camper trailers use both 12 volt and 120 volt systems. The 12 volt applications are usually small light systems. Set the multimeter to 20 volts for testing the connections. With the electrical current on, the voltage on the display should read at least 12 volts when touching the connections with the probes.
All of the other electrical systems on board your camping unit will most likely be 120 volts. Set the multimeter for 200 volts and make sure the electrical testing probes are in the proper inputs. The digital display on the multimeter should read 000. Insert the probes into an outlet, making sure the power is on at the breaker box. The multimeter display should be in the 110-120 range.
Use this setting to test circuit breakers in the main breaker box and also GFCI type outlet applications in the bathroom and kitchen areas. The electrical power to the A/C and H/W heater and various other vent fans should all test in the same range.
After you become accustomed to using your new multimeter, you will discover it can be used for your home, car, or RV. A good electrical testing multimeter will pay for itself many times over and save you time and trouble in the process.
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Thanks, Drwibble! I planned to add the longer leads to the article and also include some in the ads. Too sleepy to remember, I guess. I use a multimeter lots too, both in my job and around the home.
Thanks again for reading and commenting!
Interesting reading, not the best in the electrical department so this has been helpful, many thanks.
It isn't as complicated as it looks, kiwi gal! This is a great electrical problem solving aid. Thanks for the comment and for reading my hub.
Randy
Randy Godwin, these are good tips. As an old sparky and having blown up a number? of MM's in my day I would like to suggest to your readers that when measuring Volts to always start with the Higher settings and work your way down until you get a readout :-)
Excellent advice, agvulpes! I tend to forget the simpler things. Thanks for the tip!
so I have just acquired a 92 5th wheel for free. of course there are issues, the most critical is the electrical. this trailer has had 2 lightning strikes. the first blew the control board on the frig and the 2nd has also disable the frig. after examining it i found the common wire has melted out of its insulation. no obvious burns on the board itself. how does one actually test the board for being bad? i never run a fridge on gas btw
I would test the heating element instead, xactdude. If it is getting the proper voltage the board is probably okay. Those circuit boards will burn out fairly easily, in my experience.
Randy
thx randy, that makes sense, i have a sneaking hunch the converter is gone also, the electric jacks are acting like they are low on voltage also and wont turn. can u advise where i can get the tech info on the voltage requirements?
Are asking about the voltage requirements of the jacks or the converter, Xactdude? The converter should be putting out around 13 volts DC to the batteries when they require charging.
You might try checking the voltage at the jacks while operating them to find out if the batteries are storing enough amperage to work properly.
Randy
will do it, thx
Drwibble 2 years ago
I do a lot of electronic repair. I would be lost without my trusty multimeter. One thing I would advice is to buy some extra long leads with crocodile clip attachment. This come in very handy for fault finding across long wires which are fixed in place.