Troubleshooting and Repairing RV Electrical Problems for the Beginner
The Novice and Electrical problems
An RV is a complicated Electrical machine
The RV that you see today is a complicated machine with a lot of built-in electrical devices.
And, along with these devices comes complicated electrical control and protection circuitry.
This article is written to provide some basic but valuable information for the typical RV owner to help them with defining and repairing Electrical problems efficiently and safely.
Electrical Safety comes First!
ELECTRICITY Can KILL!
Please remember this when reading the information listed below.
The information provided here is for you to reference, and in no way should it be abused or used by someone that is unqualified to perform electrical repairs..
First, when you start opening panels and messing around with Electrical systems, in an RV/Camper or at home.
There are several warnings you must observe;
WARNING-1- If you do not know what you are doing, do not touch anything, and call your RV manufacturer, or RV Roadside assistance Company, or if at home, your local Certified Electrician. Remember, again, ELECTRICITY CAN KILL!
WARNING-2- If replacing a BLOWNFuse, or resetting a KICKED Breaker doesn’t fix the problem, you should seriously back off and call your RV manufacturers Service Center for advice.
Typical Coach Batteries
Know the difference in a Major and a Minor electrical problem
Is there a Major Problem?
The RV owner, or especially the RV renter, should always make a walk-around inspection of their camper before they go on the road.
And one of the main things that they should be familiar with is the electrical system of the RV.
Oh, I'm not talking about knowing how to perform major maintenance on complex electrical gear and appliances, but rather know how to inspect for problems, and determine if the problem is major or minor.
A major problem might be having the fridge quit working and deciding whether to get into the wiring and propane management circuitry on the back of the fridge or not.
The electrical novice needs to stay away from such repairs, themselves. They are too dangerous and you should always contact a qualified service tech for resolving such problems.
But, a minor problem could be something as simple as re-setting a breaker that has "kicked out", or replacing a blown fuse that is easily accessible, or some other simple problem.
When my old multimeter died, I selected this one for its functions, ruggedness and ease of use.
One handy device for the RVer to have is a good Electric Multi-Meter.
There are very simple electric devices that you can plug into the wall, and an LED lights to indicate that there is power.
And on the other end of the spectrum of electrical testing devices is the Electric Multimeter.
This Multimeter is capable of measuring DC Volts, AC Volts, as well as electric current and resistance.
This device is very useful in the hands of a trained individual, but the Novice should not attempt to use all of it’s functions until they understand what they are trting to measure as well as any dangers involved in making the measurements.
Think before touching Electrical contacts
I cannot stress this enough. Your Camper or RV was designed by professionals who planned things out pretty well..
They designed the electrical systems with Safety in mind, as well as for your convenience.
Each electrical device was installed on an electrical line that could safely handle the load.
The fuses and breakers were placed in the system for two major reasons.
1-The first reason is to protect the RV and you the owner from harm if an appliance or other electrical device or even an electrical line fails and draws too much current.
2-The second reason is to protect your RV and it’s electrical appliances and other devices if you plug your RV into an electrical service that is not regulated properly and you get electrical voltages that are too low or too high for your RV and it’s equipment.
So, when you get a blown Fuse or a kicked Breaker, your first thoughts should consider these highly probable causes. Especially, before you go tearing into your electrical system, and personally re-designing it by installing a larger than specified Fuse or Breaker.
Think, Think, Think, and then Think again.
Useful Electrical Terms and data
I have provided a long list of Electrical Terms and color codes for fuses, along with other useful data designed to help the novice be more comfortable with what they are doing when an electrical problem does occur.
Defining Some Electrical Terms
AC-------- AC is the designator for "Alternating Current" The voltage in your home is AC voltage, and typically, in the US is assumed to be 115VAC. Alternating current reverses polarity and flow alternately in both directions in a circuit.
Amp------ The name Amp is used to designate a measure of electrical current.
Capacitor- A capacitor is an electrical component that can store electrical energy, in other words it has a specific electrical storage capacity. A Capacitor often has a polarity and must be installed properly. The polarity is generally indicated by a stripe at one end of the part.
Circuit Breaker----- A Circuit Breaker is a device that is designed to open up or "throw" itself, when the current through it exceeds it's designed limit. Unlike a fuse, a circuit breaker can be reset when it throws. FYI- many people do not realize that, if you have as circuit breaker that has kicked our regularly, it probably is no longer functioning at the original current level. It is a electro-mechanical device, and after repeatedly kicking out, it will often suffer from mechanical stress, and not be able to hold at the original designed current.
DC--------- DC is the designator for "Direct Current". Direct current flow constantly in one direction, commonly from the Positive lead to the Negative lead of a battery for instance.
Diode----- A Diode is an electrical component that allows current flow in one direction and impedes current flow in the opposite direction. The ends are designated as the Cathode and the Anode. The Cathode is usually marked by a stripe at the cathode end, and it allows current flow is from the cathode to the anode.
Fuse------ A fuse is a device that is designed to destroy itself or "blow" when the current that passes through it, exceeds it's designed current limit. It is a safety device used to protect electrical devices under adverse conditions. When replacing a fuse, always use one with the same current and voltage rating.
GFCB----- A GFCB or Ground Fault Circuit Breaker is designed, similar to a regular circuit breaker, to "throw" itself off when the current through it exceeds its designed current limit. Additionally, a GFCB will throw itself if even a small amount of current is detected between the "Hot" leads and the ground lead of the circuit breaker.These specialty circuit breakers are required in areas such as bathrooms, kitchens, and garages. These places are sites where the user of an appliance could possibly be physically touching ground through plumbing, metal or concrete floors, etc, and using an appliance that is not insulated properly. They are life-savers.
ohm------- The word ohm is the a value of resistance to current flow.The resistance can be calculated using the formula: R=V/I, or Resistance equals Voltage divided by current.
resistor---- A resistor is a passive component used in electrical circuits to provide resistance to current flow.
Watt------ A Watt is a measure of electrical power. DC Power can be calculated using the formula: W=V x I.
Wire Gauges----- Wires used in electrical circuits come in many sizes. The size of a wire is selected by the designer to handle the specific current that passes through it, with minimal resistance to the current. Standard wire sizes or gauges go from 0 to larger numbers. The larger the gauge number, the smaller the wire size.
One-Letter Electrical Abbreviations
f----------- The lowercase letter "f" is a designator for the value of a capacitor called "Farad". Ex: 1uf mean 1 micro-farad.
I------------ The uppercase character "I" is the designator for electrical current or the Ampere, or Amp. Current can be calculated by using the formula: I=V/R, or Current equals the voltage divided by the resistance.
K----------- The uppercase letter "K" is a designator for Kilo" or numerically 1000 would be one Kilo-unit. Ex: 1-KW means one Kilo-Watt.
m---------- The lowercase letter "m" is a designator for "milli" or numerically 0.001 would be one milli-unit. Ex: 1-mW means one milli-Watt.
M---------- The uppercase letter "M" is a designator for "Mega", or numerically 1,000,000 would be one Mega-unit. Ex: 1MW means 1 Mega-Watt.
n---------- The lowercase letter "n" is a designator for "nano", or numerically 0.000000001 would be one nano-unit. Ex: 1-nf means 1 nano-farad
p----------- The lowercase letter "p" is a designator for "pico", or numerically 0.000000000001 would be one pico-unit. Ex: 1-pf means 1 pico-farad.
u---------- The lower case letter "u" is a designator for micro or numerically "0.000001" would be one micro-unit. Ex: 1uf means 1 micro-farad, a value for a capacitor.
V---------- The "V" upper case "V" is the designator for an electrical unit of Voltage. Voltage can be calculate using the formula: V=I x R.
W--------- The upper case letter "W" is a designator for Watt.
Resistor Values and Colors
Gold (as the fourth band)
1% tolerance on the value
Silver (as the fourth band)
5% tolerance on the value
No color (as the fourth band)
10% tolerance on the value
The Problem is not Always Electrical
There could be other causes for your problem
This is a very important thing to consider when you have a blown Fuse or Kicked Breaker in your RV. Remember, as I mentioned already, that your RV is a complex home on wheels.
Many of the appliances in today’s RV operate using; AC-voltage, DC-voltage, and Propane Fuel either individually or in combinations..
Often, even when in the Propane Fueled mode, the appliance will require DC-voltage for the Logic circuits.
And many appliances have sensors on their mechanical parts that will kick a Breaker or blow a Fuse, rather than allow the appliance to continue running in an unsafe mode.
How to Use a Multi-Meter
FUSE RATINGS for replacing blown Fuses
In case you do not know this, standard Automotive Fuses are color-coded according to their Current rating, so what I have below is short list for your reference.
One note here though; If you have a blown fuse, replace it with the same rating blown fuse. NEVER use a higher rated fuse in place of a blown lower rating fuse.
There are so many things wrong with this, but there are 2 things at the top of the list that can happen; 1)- You can cause an electrical fire and destroy your RV, and 2)- You can cause the equipment fed by that fuse to be permanently damaged. Always remember, the fuse was designed for a normal operational load. And if it blew, something has changed.
The Color of a Fuse Shows Its Amp Rating
Amperage rating (amps)
How Much Current Do Your Appliances Draw?
Too much current (amps) will causes your fuses, breakers, and ground fault detectors to shut off as a safety measure. Too much current can melt wires, ruin appliances, and start fires.
It's good to know which of your appliances use a lot of current, even when they are working properly. That way you can decide when and where to use your appliances so that the flow of electricity stays within the bounds your system can handle.
The table below lists the approximate MAXIMUM current drawn by the referenced appliances in your RV. Most appliances draw a lot of current during a short period of intense use and less at other times These current figures are not exact and may vary by manufacturer and model.
Air Conditioner (Maximum use at startup ) (rated 13,500 to 15,000 Btu)
At startup, this is the peak
Air Conditioner (normal rate after it gets going)
Coffee pot (Maximum use, while perking coffee)
Once the coffee is through being brewed, the hot plate under the pot uses much less. Turning the temperature down on the hot plate will reduce operating current.
Less powerful hair dryers might be better for RV use.
Crock pots are useful for cooking in RVs
Electric Frying Pan
Hand Vacuum (small)
1.5 to 5
Depending on the size, the manufacturer, and the technology.
Water Heater (in 120-volt AC mode)
Estimating Maximum Current
If you are unsure of what current an appliance draws, use this simple method to calculate the maximum current it will draw when working.
1. Look for the appliance's power rating in WATTS. You may find it on a label on the appliance, or in the owner's manual, or you can contact the manufacturer or look online.
2. Divide number of Watts by 120 (the AC Voltage), and the result, in AMPS, is the maximum rating of the appliance for current.
Measuring an Appliance's Current Use With a Tool
If you suspect an appliance of drawing too much current, use this handy meter and monitor what it actually uses. This is a valuable tool for your toolbox.
How to Calculate Current for most Appliances
Air Conditioner – 13,500 – 15,000 BTU ----- 12-14 Amps
This is the start-upPeak Amps, and Compressor Cycle Maximum Amps. As mentioned in other Blogs, while an AC might run at around 5-8 Amps, it takes a strong surge of current to start the AC and its Compressor.
Coffee Pot ----- 8-10 Amps
This is the Max for when the pot is perking. The current should drop, when only the hot plate is on, after the Coffee is perked. On many pots you can turn the hot-plate temperature down, which will result in a lower operating current.
Hair Dryer: ----- 8 – 15 Amps. The wife and I argue a lot on whether we should keep the “Mega-Amp” monster she loves to use, or get a lower Amperage (and thus heat) rated one for our RV.
Crock Pot: ------ 1-2 Amps. This is a great tool for cooking many foods in an RV.
Food Processor: ----- 3 – 5 Amps
Frying Pan (Electric): ----- 7 – 11 Amps
Hand Vacuum (small): ----- 2-Amps
Iron: ----- 8-10 Amps
Microwave Oven: ----- 8 – 13 Amps
Microwave Mode/Convection Mode, with Conv. Mode being at the highest.
TV Digital: ----- 1.5 – 5 Amps. Dependent on the Manufacturer, Size, and type of technology.
Water Heater, 120 VAC Mode: ----- 11 – 13 Amps
If you are unsure of what an appliance draws use this simple method to calculate the Current:
1- Check the label on the Appliance, if that’s not available, check your Owners Manual, or contact the manufacturer, and find the power rating of the appliance in WATTS.
2- Divide the Watts number by 120 (the AC Voltage), and the result is the max CURRENT rating of the Appliance.
Some Electrical Tips for the RV owner
When all is said and done, there are some things that every RV owner needs to realize about their "home on wheels".
Traveling and Vibrations
A camper, regardless of whether it's a motorhome or a tag-along trailer, vibrates a lot when in transit. And, these vibrations will, at times, literally shake electrical connections loose.