In part 3 of this four-part series regarding your RV electrical system, we will be discussing system troubleshooting. In case you missed Part 1 and Part 2, be sure to check them out too.
Given the importance of the RV electrical system, and the fact that many electrical problems can be fixed with a little knowledge and the right equipment, I highly recommend all RV owners invest in a digital multi-tester. They are inexpensive and invaluable when tracing power problems. If you don’t have a meter, they can be purchased from a local home improvement or electronics store or found online. If you don’t know how to use one, a wealth of information can be found on the internet.
If you have problems with a 12V component in the RV, the first thing to check is the fuse protecting that circuit. Most fuses are mounted together in the power distribution center. It is important that RV owners know where the fuses and breaker panel is located. It is sometimes difficult to tell with the naked eye whether a fuse is blown, so it is always a good idea to “ohm” out a fuse with a multi-tester to determine if it is blown. Some 12V systems have inline fuses, so if you can’t find the fuse for a given circuit in the fuse panel, search for an inline fuse. 
Inline fuses are required to be installed within 18 inches of the batteries, so you can often find inline fuses near the batteries.
Make sure you locate a fuse for any 12V system you are troubleshooting, as that is the most common cause of failure. Be aware that a single fuse may protect more than one device. If the fuse isn’t blown (be sure to check it with a meter), look for loose or broken wires. This can be difficult, but once again, a meter comes in very handy to probe the voltage along the wire. Since the wiring is often hidden behind walls and other structural members, access will be limited. The best thing to do is check for voltage at the effected device, such as the water pump. If you have voltage there, but the device isn’t working, it is likely the device has failed. If you don’t have voltage there, check for voltage at the switch or control board. It is also important to check the battery voltage, as low voltage can cause intermittent and random problems. Most 12V devices will not function below about 10.5V.
So, when troubleshooting 12V problems, first check the voltage at the batteries and/or converter. If the coach is plugged in and the converter is functioning, the battery voltage should be over 13V. Next, locate and check the fuse. Probe the failed device to see if it is getting voltage. Finally, probe for voltage at other obvious locations along the line, such as switch and control board. If you can’t identify the problem, seek out the assistance of an RV service center. If you lose all your 12V circuits, first check the battery voltage. If you are plugged in to shore power and you lose your battery voltage, check your converter fuses and breaker. The converter will have a breaker on the output and fuses on the input. If the converter is separate from the power distribution panel, it will likely be installed behind a coach wall (likely behind the breaker panel), and will have to be accessed to check the fuses. If the breaker and fuses are okay, your converter may need to be replaced.
Next week I will finish this series with a continuation of electrical troubleshooting
About the Author:
Steve Froese, an avid RV owner, traveler, and Coach-Net member since 2013, is the principal of “A Word to the Wise Technical Communications”, a published RV author, certified RV technician, and licensed Professional Engineer. He frequently collaborates with the “RV Doctor”, Gary Bunzer, and has worked with the RVIA/RVDA as a technical and training writer and consultant. Professionally, he works as a quality engineer and musician. Watch for more of Steve’s work in upcoming Coach-Net publications.
This article is the second part of my electrical system primer. This week I will cover the 120V AC system.
When the coach is plugged in, the shore power is shared between the 120V AC appliances and the converter or inverter. Most coaches, except after-market installs and high-end diesels, utilize converters.
but not on generator, the first thing to check is the circuit breakers on the generator. Many users may not be aware that the generator has its own circuit breakers. Locate these breakers, which usually consist of a 20A and 30A breaker, and make sure they are not tripped.
By far the largest volume of technical support I provide to RV owners is related to the electrical system. This is not surprising however, considering the electrical and propane systems basically comprise the entire house system. Many owners struggle with both these areas, but the electrical system remains the most elusive. Over the next few weeks, I will be discussing the RV electrical system.
A logical place to start is with the 12V DC system. The 12V system provides power to all the interior lights (although there may be some 120V lighting in some coaches), range hood, water pump, vent fans, and some entertainment systems. It also controls many of the LP, and even 120V AC, appliances. This causes many owners to scratch their heads when troubleshooting AC or propane problems with their coaches, not realizing that the root of the problem lies with the 12V system.
From rare California poppies to sweet-scented phlox, wildflowers begin to bloom this month across much of the country. Filling green meadows, desert basins, and forest floors, wildflowers bring a special beauty that usually can only be seen for a few weeks.
Each spring, brilliant orange California poppies, lavender-colored bush lupine, and white mariposa lilies blossom across the nation’s newest national park. To see a variety of them at different elevations and from a number of vistas, take the High Peaks and Bear Gulch trails.
From late June through early August, summer wildflower blooms are at their peak. Check out the Swiftcurrent Lake Loop Trail for meadows strewn with purple asters, white torch-shaped clusters of beargrass, and sun yellow glacier lilies, all with majestic mountains as a backdrop.
Amid the high desert is an oasis of summer wildflowers on the Alpine Lakes Trail. Spring-fed Lehman Creek flows into a lake and supports Parry’s primrose, penstemon, and phlox, all set against vibrant green grass. Butterflies are abundant here as well.
The cooktop is an important appliance for most RV owners. A cooktop is a countertop only appliance having from two to four burners and no oven. If an oven is included, it is classified as a range. Historically, most recreational vehicles were equipped with ranges. However, with the popularity of convection microwaves it is rare to see a range in an RV. In this article I will focus on RV cooktops and discuss detailed operation and troubleshooting.
Navigating your RV through urban traffic is never fun, but toss in an RV trailer tire blowout at the same time and things can get life threatening if calm heads don’t prevail. The strength of your RV driving skills is measured by how you handle unpredictable situations like blowouts. Unfortunately the only way to determine where you stand is to actually experience one of these calamities, which is exactly what happened to us while maneuvering in a mess of interstate traffic.
“We have Coach-Net! That’s what it’s there for!” I pleaded. “You have good life insurance but I really don’t need a dead husband!” I added for extra drama. Maybe that’s what did it, but he relented and with a grumble said “Fine, call them.”
Waiting for it to be over was the hardest part, but we learned much from the experience. For starters, watching the repairman do his job made one thing obvious: he knew exactly how to park diagonally behind us so that if a car hit us all, his truck would take the impact first. Those RVers who try to do it themselves without a buffer of protection on the freeway practically guarantees a tragic outcome.
Last week I published an overview article on how direct spark ignition forced-air RV furnaces work. This week I will discuss some possible failure modes and troubleshooting steps to help keep the appliance functioning properly.
With short-cycling, the furnace will shut down before the set temperature is reached. This is a common problem in very cold weather and results from the furnace overheating before the RV heats up. This is a normal occurrence meant to protect the furnace and does not indicate a faulty appliance. When this occurs, the furnace will relight when it cools down. Short-cycling may occur more than once in a heating cycle, but eventually the RV will reach the set temperature and the short-cycling will stop. If your furnace short-cycles, be patient, as it may take slightly longer for the RV to heat up. You may choose to slightly reduce the set temperature.
If the furnace blower starts and the burner tries to light but fails, I would first check the propane system. Make sure your other propane appliances are functioning properly. It is a good idea to have your propane system inspected annually by a qualified RV service center.
In my last two columns I have been discussing the RV water heater, and this week I will extend the appliance discussion to the furnace. Because they are so inherently reliable, RV appliances are often taken for granted until they fail. Furnaces are perhaps the strongest example of this, as they rarely fail, and even when they do, it may go unnoticed until the cold weather sets in. This can make for a long, cold day or night. There is not much to worry about in an RV furnace, but in this two-part article I will present the basic furnace theory of operation and some repair and maintenance issues. Note that this article will deal exclusively with direct spark ignition (DSI) ducted forced-air furnaces, as these are the most common models in most recreational vehicles.
The DSI furnace heating cycle is as follows:
It’s no secret: RVers have a well-deserved reputation for being thrifty. Many say that’s why we take our homes on vacation; we’re too cheap to pay for hotel rooms! All kidding aside, I have to admit many RVers like me really do possess a flair for frugality. On rare occasions however, we surprise everyone, including ourselves, by opening our wallets to be a bit more comfortable. After doing so the inevitable question follows: “What took us so long?!” For example, here are three of the best RV upgrades we wish we did sooner:
Some RVers set up camp with all the accoutrements. Not us. We started full-timing in a 24′ fifth wheel with zero room for unnecessary gizmos like twinkly awning lights and telescoping flag poles. We refused to carry items we thought didn’t add much value to the RVing experience, like sewer hose supports and plastic leveling blocks. Living without a sewer hose riser has never been a problem and even sloped campsites never bothered us too much in our smaller rig. But since upgrading to a longer and wider fifth wheel, uneven ground is more annoying than ever. Our rig lacks hydraulic levelers, so last Christmas our practical-minded gift to one another was a $35 set of leveling blocks. After using the blocks from California to Texas, we’re on the level and loving it! Gone are the days of cabinet doors smacking us in the face whenever we open them, or worrying about damaging our refrigerator when we’re unevenly parked. All we have to do is actually remember to use those blocks and everyone’s a happy camper.
Like many RVers, we’ve had our share of costly brake issues. From burning out brakes in the Rockies to getting ripped off by bad mechanics, trailer brakes have been the bane of our full-timing existence – and our bank account. Finally after eight years and 140,000 miles, we opted for an electric over hydraulic disc brake conversion on our new-to-us rig.
Adequate solar electric power systems start with a careful energy audit of your power consumption. Better solar electric power systems end with your willingness to commit a little more money to the project. Our first system was woefully inadequate mainly because our small rig lacked battery storage space – but mostly because of our reluctance to spend more cash. For seven years the system barely met our needs as we limped along during cloudy days. When we finally upgraded to our 27′ fifth wheel, I eagerly surrendered a storage compartment for a bigger, better battery bank and inverter. Cutting the check wasn’t quite as easy but now we can enjoy camping luxuries like running the microwave and our vacuum – a must when you live with a German