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. 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. 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. 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. 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
      [email protected]

  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. Steve / Customer Service

      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
      [email protected]

      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.

    1. Steve / Customer Service

      Good morning Dave,
      It is always best practice to disconnect the battery, as you don’t want up to 300amp going back through the system

      Kind regards
      BMPRO Customer Service
      [email protected]

  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.

    1. Stewart / customer service

      Good morning Maxwell,
      This could be caused by a solar short in the system do to the voltage. We would recommend that the dealer looks at the caravan be straight away.

      BMPRO Customer Service
      [email protected]

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