As RVs get bigger, better and more complicated – so, too, do the things than can go wrong with them. Read on for some common RV problems and how to fix them, quickly!

The desire to add bigger, better and more fantastical features to our RVs has led to a new range of problems which weren’t part of the scene several decades ago, when times were a little simpler. But the fixes are often simple – if you know where to look or what the issues are, and often don’t take too much in the way of tools or techniques.
Here’s a few common RV problems that have come across our desk recently.

After I picked up my new van, I discovered that my solar panels weren’t working, and even when I plugged in my portable solar panel, that wouldn’t work either. What’s the issue?

It sounds like there was no diode or fuse between the panels on the van. If one was faulty and they are not isolated, it will prevent them all from working. In this situation, you need to disconnect all panels (there is likely a junction box where they join up) and reattach them one at a time until you find the faulty one. Leave it disconnected until you have time to replace it.

I have an 80 litre upright fridge but it continually ices up on the back wall. How can I stop this?

Small upright fridges generally make their cold in the back wall and are so crammed with food that it cannot spread around the fridge’s interior. You’ll probably notice that items at the front of the fridge won’t be as cold. Have a small fan fitted to blow diagonally on to the centre of the rear wall. It will move the cold air away and prevent the icing.

My tail lights and/or blinkers are not working. Is there an easy fix?

If you have a flat seven-pin plug, it’s likely that the split pins on either end of the male plug have been squashed when attaching and unplugging. Use a small knife blade to open the gap in the pins to reestablish a good contact.

My fridge constantly cycles at times and eats up electricity from the batteries. How can I prevent this?

This sounds like a temperature issue. If the fridge is located in the sun or the interior of a hot car, or even on very hot days of high ambient temperature, some fridges struggle to keep the interior cool and have to work constantly, especially upright designs. A wet towel on top will help greatly, or simply moving the fridge into the shade. Keep opening the fridge to a minimum, reduce internal air space with inflated wine cask bladders or similar, make sure door or lid seals are working well, and add an insulating cover to help.

My batteries never seem to fully charge when on the road, and the problem has only got worse since I bought a new tow car. I have an Anderson plug to connect to the car’s alternator so they should charge when towing. Are they faulty?

The likely problem is a lack of current being provided from the car’s alternator. Your new tow vehicle likely has a ‘smart alternator’, which would only be delivering around 13.5 volts at best, and can be well below that and even not producing anything at all when idle.

Alternators have never been designed to fully (100 percent) recharge a car battery, much less a secondary battery in a caravan or camper. They are merely designed to replace charge lost during starting and to provide for other vehicle-only loads. Voltage losses, especially over the undersized cables often fitted to Anderson plugs, further exacerbate this.

The only solution is to install a DC-DC charger which will accept voltage inputs as low as 9 or 10 volts and which can boost them to around 14.5 volts and manage them in a three-step charging process. This is the only way to adequately ensure you can replace all of the charge lost from your storage battery while camped.

My tow rig’s braking efficiency has dropped, and I am feeling the tow vehicle veering to one side when stopping. I have had my car’s brakes checked and I am assured they are okay. Could the problem be in the caravan’s brakes?

More than likely, it is your van’s brakes that are at fault. The reduced braking efficiency when towing tells us something isn’t working well, and the kicker is the tow vehicle’s veering off line. This suggests that the brakes on one side of your caravan are not working. When you apply the brakes they don’t work but the brakes on the other side do, causing the van to impose a sideways load on the vehicle’s tow bar and producing the veering.

We’d guess something like broken or damaged wire to the van’s electric brakes on one side is the cause and is simply solved by replacing that wiring. Any brake shop should be able to affect a fix.

I have had my new van fitted with two 130 amp-hour AGM batteries which are now just over 18 months old but I have been told they are now effectively dead and need to be replaced. Surely they should last longer. I have a 100 watt solar panel on the roof to recharge them. Why have my batteries died so soon?

Without being able to test the batteries we’d guess it’s because you don’t have enough solar to maintain the batteries. 100 watts of solar is not sufficient to replace losses in a van that, we assume, is running a fridge, lights and other loads.

Fixed roof-mounted solar isn’t the most efficient and will only be operating at maximum anyway for about an hour or two at midday on a sunny day. You should not take your AGM batteries (or other types other than lithiums) below 50 percent state of charge or you will be damaging them and shortening their life. You need to assess your power needs and have a system designed to suit, but at a guess you will need at least 300 watts on the roof, make sure you stay away from shade and carry maybe an extra 100 watts of portable solar for cloudy days.

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  1. Grahame Powles

    Hello, I recently purchased a MiniBoost to connect to the Aux input on the J35B installed in our new Jayco Outback. Upon closer inspection, I see there are wires already attached to the Aux input. As these are relatively light in weight, would I be correct in assuming that these connect to the JControl hub for monitoring/management purposes and should be left in place when the MiniBoost is connected?

    Thanks for any advice.

    1. Olga kustova

      Good afternoon Grahame,

      These “light” wires are the Aux charge circuit fitted by Jayco.
      It is recommended to have a minimum of 5mm2 wire to feed the input of the mini boost.
      You may need to have external wiring fitted to meet this criteria.
      Any changes you make should be run past your local Jayco dealer as it may void your warranty.


  2. Water coming out of tank when hooked up to mains water it is only dripping take cap off and it still just drips

    1. Olga kustova

      Hi Mark, sounds like there is plumbing issue and suggest that you take van to your service centre for a review of the current circumstances to diagnosis what is happening.

  3. Karen and Mark

    We were recently made aware that our vehicle was fitted with a smart alternator and would not be charging the house batteries in the motorhome as we travelled. When we inquired as to whether we required a DC/DC charger with the dealer’s service centre they assured us that the BMpro/JHub system WOULD in fact be charging the house batteries, as that’s what it was designed to do, and we wouldn’t require a DC charger. Are they correct, or confused?

    1. Olga kustova

      Hi Karen and Mark,

      Each caravan/motor home is different.
      Check if you need a DC-DC. Turn off AC mains, test at night to eliminate solar. Turn on lights etc to bring the battery out of float and start your vehicle. If the system charges the battery to full, it does not need a DC-DC booster.

      The BMPRO system will only allow charge to pass through the AUX unregulated if the voltage on the house battery is lower than that in the car/alternator. It does not therefore allow for smart variable alternators. If you do need a DC-DC charger, install MiniBoostPRO DC-DC charger which is specially designed to work with our range of power management systems.

  4. Hello,
    I have purchased a 2019 Jayco Silverline from Watsons at Coffs harbour and am happy so far with it, a few minor fitting problems which I will get fixed under warranty, my problem is that the J-Hub has a low whineing noise coming from it, and is very annoying at night when it is quiet, it has something to do with the power as when you unplug the 240v from the van it is not there, can you help with this?


    1. Olga kustova

      Hi Mick,

      The J35 transformers can ring, some are louder than others, and some people are more sensitive, while I, as an example, do not normally hear it at all.

      If the van is under warranty, you can contact your Jayco dealer to resolve the issue. If out of warranty, please contact our customer service team for return and replacement.

      BMPRO Customer Service

  5. We have the BM Plus35-11-HA my issue is when not connected to other power supplies we get three green flashes then this annoying click and three flashes of orange, twice then back to three green flashes then click and the whole process starts over again and this occurs constantly with the clicking load enough to keep us awake is this fixable
    Cheers Andy

    1. Olga kustova

      Good morning, Andy,

      The 3 flashes and the relay clicking would indicate that you have an item plugged into the AUX input of your system.
      The Aux is designed for a car input only, so to have a relay click is normally not an issue as you don’t hear it from the vehicle.
      What is installed on this input?
      BMPRO Customer Service

      1. Thanks so much Steve for getting back to me, as it is just off the assembly line and haven’t had its maiden voyage as yet the caravan manufacturer is replacing it as tech guys are saying it is faulty, again thank you
        Cheers Andy

  6. I Have a van fitted with a J35B battery management system. Do I need to disconnect the battery when welding a small bracket on the chassis.

  7. Could you please give me some insight as to what is happening to our J35C system on our brand new 3 day since delivery Jayco Silverline. We were plugged into 240 power and the battery was also switched on at the JHub tablet when I noticed the battery was quite hot to touch. I checked the tablet and saw the battery voltage was showing 16.4 volts. A short time later the fridge warning light came on indicating over voltage which was closely followed by the J35 system shutting down. This left us with no lighting, the hot water system could not be ignited (Jayco instantaneous) system. Jayco dealer told us to turn off the battery switch on the Jhub which seems to have corrected the situation. Is it the case that being connected to 240 volt and having the battery switched on at the JHub can cause the battery to be charge to 16.4 volts and result in the J35 system shutting down? This is after the bathroom floor flooded with water on the first evening. Of course we are concerned that the battery getting hot as it did may well result in some damage to the system or worse still, a fire. Please advise.

  8. When I try to bring up the RV master main screen on my BmPro it just spins and doesn’t show any of the controls. I can control RV functions off my iPhone but can do it from the main panel. It worked great until tonight and I don’t know how to fix it

  9. Hi Ihave a new Jayco (August) the level on the grey water indicates half full when empty.
    Is there’s easy way to reset or calibrate?
    Regards Greg

    1. Olga kustova

      Hi Greg,
      Removing the tank 4 (waste tank) white plug from the control node would determine if it’s a tank issue which you will need to take up with your manufacturer or a control node issue.

      Steve / Customer Service

  10. I am purchasing a Jayco conquest renault master 19-1 campervan which has a 120watt solar panel. I have upgraded the battery to an 125amh invictor lithium and the BMPRO j35d will be used. My question is what is the maximum amp load so i can install an appropriate portable solar panel watt load?

  11. Hi Teambmpro,

    I have a Jayco Journey with a J35b, the problem I have is that when connected to 240volt mains the tablet shows the battery fully charged at the end of charging, but when away using solar and Aux (12volt car charging) using the Jhub tablet it shows two bars short of fully charged. Can drive the vehicle 4 hours does not help and with solar it shows the system turning power off as fully charged? Still showing two bars short of fully charged. Have you any ideas which could help rectify the problem if there is a problem?

    Looking forward to your reply.

    Thanks Tony

  12. Hoping you are able to assist with a query regarding my caravan.
    I have 2 x 150W Solar panels with Projecta 20amp Regulator feeding into 2 x 100ah Battery & BMPRO Genius II 30 Amp Charger – BMPRO DRIFTER Vehicle and Battery Monitoring System
    I am running a Waeco RPD190L Compressor Fridge.
    I am looking at 3 month trek next year and was wondering if there was any upgrades, that will give me more options with off the grid camping, as I start to struggle after a couple of days free camping
    • An additional 150 W Solar panel or replacing the current 2 with 2 larger Panels and will the current regulator allows for addition panel or upgraded panels to be added.

    • I believe that my Genius II 30 Amp Charger will not allow me to change over to Lithium, so if upgrading my current batteries what AH would I be best suited to with my current charger.

    Any other ideas would be greatly appreciated.
    DC to DC charge boost

    I do have an additional portable solar panel and a 2 Kva Honda Invertor if required but take up space in my vehicle.

  13. I have a jayco Northpoint 2020. The water inlet came lose for the connection and the node was drenched. This happen another time and I ran a fan on the node to dried it out and it started working. This time it isn’t working after drying it out. Does the node have power lights on it? Any way to manual override some of the functions?

    1. Olga kustova

      Hi Jim,
      There is an LED on the node between the white CAN connectors that will flash GREEN if everything is ok with the internal communication in the node. It will be a solid RED with a flashing AMBER if there is something wrong. OR it will not be lit at all. There are 2 inline fuses you can check that provide power to the node.
      It looks like you many need to contact Jayco customer service for a node replacement.

  14. New Age van with a BMPRO battery plus 35SR.
    2 tanks
    2 pumps
    My question is when tank 1 is low or empty does the system automatically change over to tank 2.
    Trek is not indicating that tank 1 is empty, but we have used a bit out of it and now pump 1 is running constantly.
    Is it automatically filling tank 1 up from the tank 2??
    Or do we have to change trek over to tank 2 / pump 2 to stop the pump running as it is now.

  15. My Franklin van has Battery plus 35 and Trek monitor. For two years it has worked well but now it will indicate a full battery and when 240 volts disconnected it will indicate 199 hours but very quickly the numbers diminish in about 1 hour and the battery indicates 10 volts and power switches off. My testing of the battery indicates 12,5 volts.

    Is there an easy solution?

  16. Hi, just picked up our jayco expanda outback (2021 model) from storage and batteries are flat despite turning off all power when stored. We have a J35D installed in the Jayco with dual batteries. We have the van plugged into mains power and the app can see AC is connected but will not power the van. When I press any of the lights it says it is in sleep mode. My question is do the batteries have to be charged to a certain level for the AC to power the van or is there a fault with the system. Thanks, Matt

    1. Olga kustova

      Good afternoon Matt,
      While you may have a fault with the batteries, the JHub can still function without them. The sleep mode means that the battery switch is turned on and on the JHub will show as brown. Press the battery icon and it will turn to grey, this will give you control of the JHub app.

      Kind regards,

  17. Olga kustova

    Hi Bruce,

    According to the manual, the negative should be removed first and refit last as per the manual. Our customer service team is contacting you with the repair options.

  18. I have a 2020 Thor Vegas with a BMPRO. The indoor temperature is reading 50 deg F with the inside RV temperature in the high 80’s. This prevents the AC from turning on. When the issue first started, I could blow hot breath into the sensor and the temperature reading would jump up and turn on the AC, but this is no longer working. Unit is under warranty but dealer service department could not diagnose the problem. How can I get this fixed?

    1. Olga kustova

      Hi John,

      The RVMaster node relies on thermistors (the sensor you would blow hot breath on) to send it temperature data. If the thermistors are not sending the correct information, the RVMaster node will not regulate the climate as required. The service center should initially troubleshoot the thermistor and thermistor wiring as it is likely the culprit to the issue you are experiencing. I would like to note that thermistors are not manufactured or distributed by BMPRO.

  19. I have a Jayco Eagle. On my Bmpro on the Diagnostics screen it shows a “open Load” on 23 and 24. What does this mean ? Thanks

    1. Olga kustova

      Hi Dan,

      The open load reading shown on circuits 23 and 24 is because the JAYCOMMAND node is looking for a generator and not finding it. We understand that many do not have a generator installed on their RV so we are going to change the diagnostic readings on those circuits with an app update so it does not display open load without a generator wired in.

  20. We have a bmpro-35, currently not connected to a power supply.
    We have a ticking noise coming from the bmpro area. Like something is cutting in/out.
    This is the middle of the night and keeping us awake is there a simple solution????
    Cheers Gary

  21. I have a j35b ańd have 350 watt solar there seems to be a auto circuit breaker somewhere where which auto disconnects is this correct and would running the two panel in series stop the breaker tripping

    1. Olga kustova

      Hi Gary,

      If the two panels are in series the voltage of the panels will be too high for the J35 and cause it to shut down, the panels should only be in parallel.

  22. Bernie van Lith

    My Water Pump won’t work. Also when toilet flushed there is a delayed beep which switches on the signal finder. How to I fix this. I have gone into setup and done Factory Reset. With no AC power connected the light goes RED when using flush and also when l switched the hub to pump on.

    1. Olga kustova

      hi Bernie,
      There is no audio speaker in our systems.
      Which system do you have fitted in your van?
      Have you spoken with the manufacturer to check if everything is wired correctly?

  23. HI,

    I recently had a 200 AH lion battery installed into our van which was replacing two lead acid.

    We have not been away or used the new battery yet so I thought I would charge it via the 240 volt external source and this is where the issue has arisen the external power blew a 35amp fuse and now we have no power at all to our GENIUS 11 30-35 any ideas what the problem may be ?

  24. Michael Edwards

    I have a Jayco Journey 19ft Outback it is fitted with a J35B system which bis connected to a 100amp battery I would like to connect another battery which is a 120amp will this cause any problems.

    1. Olga kustova

      Hi Michael,

      Yes it can cause problems.

      We strongly discourage anyone from connecting batteries in series or parallel if they are not identical in age, size and type. Different types of batteries (flooded or AGM) and brands that can have different charging and discharging characteristics as well.

      Please check out our blog post.

  25. I recently purchased a 2017 caravan fitted with a BMPRO BatteryPlus35 and a 100AH Deep Cycle battery. I want to change to a Lithium battery and reading articles on your website apparently this battery management system was not designed to work with Lithium. As a replacement system (HA model) costs close to $1000, is there another option ie. modification to the existing sytem ?

      1. Thank you for the info Olga – I checked the link at the end of your reply but cannot find my model listed. On my unit, it states BatteryPlus35 but no other letters. It does state “For use with lead Acid Batteries”.
        Can you check and advise if this model is suitable for lithium upgrade.

          1. Hi. I have had a new 200ah enerdrive battery fitted to my van hooked up with a periwinkle 2000 w inverter. My bmprow is showing 199watt in the time remaining window but when I hook up device in my van it drops straight down to 63 hrs. These hours are only on the screen for a short time. When I turn it off then back on it sometimes shows 199hrs again but then the screen goes blank a short time after. Can you tell me the problem?

          2. Olga kustova

            Good afternoon Paul,
            Which system do you have in your caravan?
            Can you please send us some photos of the battery and, battery management system and the inverter installed?

  26. We have a 2020 Thor compass 24SX. The RV master bmpro tablet is working but the menu lights will not come on. This means we can not work the slides, lights, ac etc. Can anyone help.

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