Troubleshooting RV Circuit Breakers

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When your RV is plugged in, 120-volt alternating current (AC) can run appliances and small electronics. Just like in your home, circuit breakers control AC power and allow you to plug in safely. 

But what happens when power outlets or specific appliances stop working? Troubleshooting RV circuit breakers may only be part of the solution, but it’s an important piece when troubleshooting your RV’s entire electrical system

The video above shows you how to troubleshoot electrical issues associated with pulling too much power, like tripped breakers or blown fuses, and how to fix them. Below, we’ll go into more detail about RV circuit breakers, how they operate, and how to troubleshoot them.

Understanding AC versus DC Power in your RV

Before you dive into circuit breaker troubleshooting, it’s essential to understand how RV electrical works. Here’s a short video introduction: 

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Understanding your RV’s Amperage

Most RVs are equipped with 30 or 50-amp electrical service. You can find this specification for your RV in your owner’s manual. Here’s a little more about 30-amp versus 50-amp RVs: 

Understanding your RV’s Electrical Distribution Panel

Now that you have a basic understanding of RV electrical systems, it’s time to decipher what you’re looking at in your electrical distribution panel. If you have a used RV, hopefully your distribution panel is properly labeled, but this isn’t always the case for used and new RVsPro tip: If your panel isn’t labeled, take the time to label it because it will save you time when troubleshooting future issues. 

To troubleshoot circuit breaker issues, you’ll need to know which breakers provide power protection for the different appliances of your RV. If your breaker panel isn’t labeled, consult your owner’s manual for electrical specifications that will help you label it appropriately. 

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Photo by Camping World

How Does an RV Circuit Breaker Work?

An AC circuit breaker is a protective device that opens when excessive current flows in the circuit. By opening, it interrupts current flow, and this is commonly known as “tripping” the breaker. 

The tripping mechanism is enclosed in a molded plastic case with the breaker’s rating (in amps) stamped or molded into the handle. AC breakers must be manually reset to restore current to their associated RV appliances and outlets. 

How to Check RV Circuit Breakers for AC

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Photo by Camping World

If a breaker is tripping, it’s important to check how many amps are flowing through the circuit after you reset it to make sure the circuit is not overloaded.

To test a circuit breaker, you’ll need a clamp meter that reads AC and DC amps, volts, and ohms. This allows you to clamp around a single wire to read amps without placing the meter in series. 

With a digital multimeter (DMM) or voltmeter, you’d have to connect the meter in series, which limits your amp reading to the meter’s fuse rating, which is usually only 10 amps. By clamping around a single wire instead of connecting in parallel, a clamp meter allows you to test higher amperages.

Here are some quick testing tips: 

  1. Plug your RV into a 30 or 50-amp power pedestal. 
  2. Set your clamp meter to the volts AC setting. 
  3. Make sure the breaker is in the ON position. 
  4. Place one test lead on the neutral bus bar and the other on the black wire attached to the breaker being tested.
  5. Your meter should read approximately 120 volts AC, indicating a closed breaker allowing current to flow. 
  6. If your meter reads 0 volts AC, the breaker is open. 
  7. Change the clamp meter to the AC amps setting. 
  8. Clamp around the black wire attached to the breaker being tested. 
  9. With associated loads or appliances in use, the amp reading should be less than the amp rating of the breaker being tested. 

If you get a reading that’s considerably less than 120 VAC out of a breaker after verifying you have 120 VAC in the main breaker supplying power, you may need to replace your breaker. 

You can also power the breaker off, unplug your RV’s shore power cord, and remove the breaker from the circuit. With it removed, you can set your DMM to the Ohms setting and test for continuity to see if the breaker is good or needs to be replaced.

Troubleshooting GFCI Receptacles

RVs have another form of circuit breaker known as GFCI receptacles. These look like standard 120 VAC receptacles, but they are built with ground fault circuit interrupter (GFCI) protection to shut the circuit down if they sense a fault current. 

RVs must have GFCI-protected receptacles in the bathroom, on the exterior, and within six feet of any sink. If a GFCI receptacle is tripped, unplug any electronics in that receptacle and use the Reset button (typically marked with an ‘R’) to restore power. 

If you wish to test receptacles downstream from the GFCI-protected receptacle, you’ll need a device known as a circuit tester. It plugs into downstream receptacles and has a test button that should trip the upstream GFCI receptacle if the system is functioning properly. If it doesn’t trip, it usually signals a defective or miswired GFCI receptacle.

Other Potential Issues with RV Circuit Breakers

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Photo by Camping World

Suppose your circuit breakers and GFCI receptacles are all functioning properly, and you’re still experiencing a lack of power to certain RV appliances. In that case, there are a few other issues to check: 

  • Blown 12-volt DC fuses. Many new RVs are equipped with distribution panel indicator LED lights that light up if the fuse is blown and there’s a load on the circuit. The best way to be certain if a fuse is blown is to remove it and inspect it visually. Blown fuses must always be replaced with fuses of the same rating.
  • Unreliable shore power. You should always use a surge protector when plugging into a power pedestal at an RV park. This will alert you to power issues like low voltage and protect your RV’s electrical system from damage. 
  • Faulty wiring connections. Even some new RVs experience wiring issues from the moment they roll off the factory lines. If you suspect a wiring issue, contact your local Camping World for professional assistance. 

RV electrical systems can be somewhat confusing to new RVers. While we encourage everyone to learn more about their RVs, you can always come into a Camping World Service Center and have a certified RV technician troubleshoot circuit breakers and other electrical issues for you.

If you’re curious about how frequently you should be servicing RV components, check out our downloadable RV ownership and maintenance booklet!

Do you have any specific questions about troubleshooting RV circuit breakers? Share them in the comments below! 

  • Comment (18)
  • William Rentz says:

    I have a class c RV. The circuits from the converter to the 12 volt circuit breaker board, it charges the rv battiers but it will not operate the AC, Slideout or anything 12 volt. What can I do to fix this?

    • Hi William,

      Can you provide a bit more information? What are the operational differences you’re seeing when plugged into shore power vs being unplugged?

      If unplugged, I wouldn’t expect your AC to work unless equipped with a soft start (or when your generator is running). If you can further describe this issues you’re seeing in which use cases, we can help you hone in on the issue. Or, you can also contact our Technical Service hotline here: 1-866-838-5304

  • Calvin says:

    Tucker, I have a problem driving me nuts, I do not have running lights when plugged into tow vehicle, I can cross the plug on camper to turn running lights on, I have power on the vehicle plug, when I plug it in, I have no running lights, I know there are 2 auto-reset circuit breakers on camper frame, how do I check these, they have 2 poles , 1 copper color, 1 stainless color, any help would be appreciated. Thanks

    • Hi Calvin,

      Sorry for the delayed reply, but I wanted to reach out to our technical service team to get their thoughts. Here’s their reply:

      You state that when you jump the 12vdc charge line on the 7-way cord plug to the running lights terminal on the plug that the running lights work. If this is true, there cannot be anything wrong with the mini breakers, since if they were bad the lights would not have worked when jumped due to an absence of power on the charge line terminal.

      Next, the power on the charge line terminal in the tow vehicle socket is good to know, but it just charges the RV’s battery and isn’t what powers up the running lights. The running lights are powered through the tow vehicle’s power distribution center, or fuse box. This is located in the engine compartment in most tow vehicles.

      The fuse for the tow vehicle’s running lights is usually not the circuit that powers the RV’s running lights, but there should be a separate set of fuses for the trailer lighting circuits in the same fuse box or an auxiliary fuse box nearby. These fuses are not typically installed by the tow vehicle manufacturer and must be handled by the hitch technician during the hitch installation.

      If this is a first time DIY install, look for the trailer section in the fuse box and ensure all fuses have been installed. If it has been working and recently failed, check the same location for blown fuses.

      If the 7-way socket has recently been installed or replaced, double check the wiring and connections. Note that on some tow vehicles, relay kits must be installed to allow the 7-way system to function properly.

      As for the mini breakers, different manufacturers utilize a number of methods to identify which lug is for Line (battery side) and which is for Load (component being powered) including “batt” and “aux or load” designations, the battery lug may be shorter than the aux/load lug, or the battery lug may be copper while the aux/load lug is silver. The relays may auto reset once they cool down, or they may have a manual reset pushbutton on the end.

      Hope this helps, but let us know if it brings up any additional questions!

  • Keith says:

    I bought my 2003 Monaco from Camping World just outside of Tampa. I bought the Good Sam Extended Service Plan because the coach was 13 years old. I DID NOT KNOW CAMPING WORLD/GOOD SAM WOULD DENY MY ATTEMPT TO CONTINUE THE PLAN AFTER MY COACH WAS OLDER THAN 20 YEARS!!!
    I have two fuse boxes outside (in engine bay & street side in front of front tire). I have an inside fuse box in my closet and I have 2 breaker boxes in my bedroom. The two outside fuse boxes have multiple and sometimes a whole banks or sets of fuses with red lights on. I checked the fuses and they are all good.
    This does not happen when the generator is on. It only happens if the engine is running.
    I have NOT checked with both the generator running and the engine on. Nor have I tried it with shore power.
    Is this normal and if not what would cause this?

    • Hi Keith,

      I apologize for the delayed reply, but I wanted to reach out to our technical service team to get their insight. Here’s their reply:

      In Monaco and Newmar units with this set up, the circuits for the chassis power systems would only be active when the engine is running. These compartments house circuits from both the house and chassis systems. Some circuits are always separated from one another, while others may run on either power source. If there are no power issues evident, then this is likely a normal condition. Do take note, however, that weather and humidity can cause light oxidation on the wire connections and fuse terminals in these outside compartments. From time to time, it may be necessary to clean these and then apply a dielectric grease to keep the air and moisture from getting to them.

      Hope this helps!

  • Jessie says:

    Hi. We just replaced the rotten floor in the rear end of our 2000 Thor Glide Lite 23’ camper. We are having some weird electrical issues that did not exist before our renovation. We reinstalled the furnace and re-wired it just as before, but it isn’t working. The water pump is also not working, and we didn’t touch it/wires or work near it. (Fuse seems ok on water pump).

    We took it out for the weekend knowing we would not be using either of those features only to discover that no appliances/outlets were working when running off the batteries (which are less than a year old and had been plugged in to charge for 2 days).

    If we plug into the generator however, microwave, fridge and outlets have power but still no H2O pump or Furnace power. Lights and bathroom fan run when not plugged into generator, but are dim and fan is slower. When we plugged into the generator, lights got way brighter and fan noticeably sped up. No breakers were tripped on converter, converter only seemed to work when plugged into generator. Is this an inverter issue? Please help!

    • Hi Jessie,

      Sorry for the delayed reply, but I wanted to reach out to our technical service team to get their thoughts. Here’s their reply:

      That model probably doesn’t have an inverter that runs the entire coach. The converter only runs when connected to 120vac by design. There may also be a battery disconnect somewhere that must be kept in the on position. There may be fuses on the converter or near the batteries. Once these operator issues are corrected, any remaining issues can be tested separately. Given the recent renovation work, I would look for pinched wires or screws/nails driven through wiring. There are also junction boxes and molex plugs that may have been pulled apart inadvertently during the repairs.

      Let us know if you have any follow up questions!

  • Alec C Apple says:

    i own a 2018 forest river vibe and my dometic duo therm ac unit has started to randomly shut off and will some times pop the breaker adn it will shut off for hours until you reset it again help please!

  • Randy says:

    I own a Southwire Surge Guard Model 44260. when I plug it in a outlet it shows “no Power’ (2 white lights) however my Travel Trailer has full power, any Thoughts?

  • David Newhouse says:

    I have a ’78 5th wheel, and I just started using the Air conditioner in it (ceiling ac), and today, which was a very hot day, my 240v power cord got hot and the plug melted a bit. Thank God it tripped the breaker on the building it’s plugged into, but when it cooled off, i plugged it back in and couldn’t get power to it. No matter what I did. The breaker switches in the RV are switched to the on position, and the buildings circuit breaker is also turned on (I triple checked, turned it off and back on several times..), so I turned them back off and unplugged the trailer to check the source. The plug in on the building has 120v going to both the primary and neutral, so there is power going to the outlet. I tested the cord for my RV, there’s power going clear to my circuit breaker in the RV. So I pulled the circuit breaker switches(2), and tested for continuity in the in position, beep on both. But absolutely no resistance in the on or off positions. Must be blown circuit breaker switches, right? Any feedback would GREATLY appreciated.. it’s so hot where I live!

    • Hi David!

      I reached out to my technical team to get their perspective. Here are their thoughts:

      It sounds like the shore cord may be bad, but more testing is needed. When testing the system, leave all but the Main breakers off in the coach for testing. Once power is restored to the Main breaker in the coach then test remaining circuits individually.

      Getting a beep is no substitute for an ohms reading. If it melted a bit, it should be replaced. Just because the a/c doesn’t work isn’t proof that there is no power to the coach. We must check for voltage and polarity at the outlets and voltage at the a/c.

      Given this is a 78, you’ve probably used this coach a lot and never experienced this issue.

      So here are a few questions:

      -Are you plugged in to 120 or 240? 240 will ruin the coach.
      -Are you using a 15amp adapter? You cannot safely run the a/c on 15amps.
      -What was the voltage at the outlet? 120 exactly or 108? Low voltage increases amps, and heats up the plug.
      -How many amps was the a/c pulling? If it is going out the amps will go high or low. It should pull 15 to 18 amps for a 15k, and 10 to 14 for an 11k.

      The breakers when removed should read at or near zero ohms in the closed or on position, and O.L. in the open or off position.

      Do you have any follow up questions?

  • Woodrow Riley says:

    In a camper when electric is hook up do you leave the main breaker on and the battery hook up too

  • mike mason says:

    Do all surge protectors show the voltage coming out of the sorce ? Thanks

  • Hi Woodrow!

    The short answer is yes. Your battery should remain hooked up, as certain appliances require 12VDC. And the main breaker on the AC side must be on for AC appliances to function.

    Let us know if there are any other questions we can clarify!

  • Hi Mike!

    Not all models offer an LED display with voltage metrics, but you will find that on models like this one:

    https://www.campingworld.com/southwire-surge-guard-portable-30-amp-120-volt-bluetooth-capable-surge-protector-118086.html

    Hope that’s helpful!

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