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Why Do RV Lights Dim and Brighten?

why do my rv lights dim and brighten

As any RV owner knows, nothing’s better than hitting the road in an RV. The freedom and comfort that an RV provides are unmatched by any other vehicle on the market. However, being a good RV owner is crucial when owning an RV so you can avoid problems, and solve them if they do come up. 

One problem that seems to come up pretty consistently for even the best RV owners is that the interior lights of the RV begin to dim and brighten. What causes RV lights to dim and brighten?

The main cause for interior lights in an RV to dim and brighten inconsistently is a faulty battery or converter.

Causes for RV Lights to Dim and Brighten


The reason that the interior lights of your RV are getting dimmer and brighter inconsistently probably has to do with the battery. 

If your lights are running off of the battery, make sure that the battery does not need to be charged. If the battery does need to be charged, dimming lights are one of the first signs of this. Charging your battery can be an extremely easy solution to this problem. 

If you’ve charged your battery recently and this is still happening, it could be a problem with the battery itself. An old battery that does not hold its charge well most likely needs to be replaced. Don’t be stingy with that battery, as you want your RV to have consistent and working power at all times! 

If the battery is relatively new, a bad converter could be what is draining your battery quickly. We will discuss this below!

The battery could also not be charging properly due to having corroded or dirty terminals. If this is the case, try dripping a little bit of cola if you have some on hand (or can buy a bottle at a nearby gas station or another market) onto the corrosion while the battery is OFF.

This may work to combat certain types of corrosion that can build up on battery terminals. Wipe it up and let it dry before starting the battery again. 

If you are looking to replace your current RV battery, then we recommend using an AGM battery like this one by WEIZE. These batteries also use AGM technology, which keeps everything sealed, and is in a tamper-resistant container. This battery can also withstand harsh temperature changes, cold or hot, which makes it an ideal battery for an RV.


If nothing seems to wrong with your RV’s battery, the converter could be the issue. This could cause either the dimness, similarly to the failing battery, or the random spikes of brightness as well, and could even be responsible for both.  

This happens because if your battery isn’t working properly or is working inconsistently, or your converter is working inconsistently, the lights won’t receive the proper power. This can cause your lights to dim, but not remain dim for as long as if the battery itself was dying. This would cause a sort of inconsistent dimness. 

When this dimness occurs, the converter could suddenly kick in and cause a sort of spike in brightness as well. If you are not only experiencing sudden dimming of your RV’s interior lights but sudden spiking in your interior lights’ brightness as well, this is a tell-tale sign of a converter that is failing. 

If you expect this to be the case, get a voltage meter and test the output of your converter. These can be found at auto body shops, repair stores, general stores, electronics stores, and many other places. 

If your converter is putting out less than 12V regularly or is dipping below 13V consistently, this could be a cause for the inconsistent surges and/or lack of electricity going to your RV’s interior lights. 

Finally, also check if there is anything blocking airflow into your converter, as this could cause issues that don’t allow it to function as intended.  

What to Do if Your RV’s Lights Are Dimming and Brightening

How to solve this problem revolves almost entirely around what is causing it in the first place. Look to the above reasons why the issue could be happening and attempt to diagnose what the problem is. After doing that, scroll back down to this section where you can figure out how to solve your problem.

If your battery terminals are corroded, consider the cola solution outlined above. This would be an exceptionally cheap option for cleaning corroded battery terminals. A similar solution is a mixture of baking soda and water applied to a toothbrush or similar bristle brush.

Simply mix one teaspoon of baking soda and twelve ounces of water, dip the brush in, and brush until the corrosion is gone. Again, make sure that the battery is OFF before you do this. 

If the battery itself is dying, it is time to get a replacement battery. There are ways of elongating a battery’s life, but honestly, the best way to go about it is to get a new one.

The battery is far too important of a part to cheap out on, as it powers a ton of the crucial functions that make your RV into more than just a glorified bus. Make sure you replace your battery around once every five years or so. 

If it is problem with your converter, there are a number of ways you can go about fixing it. Firstly, check to make sure the airflow isn’t being blocked. 

Make sure all the wires and connections in your power converter are connected. This can be fixed with a soldering iron if you have the know-how. If you are not proficient in electronics, this is better taken to an auto mechanic or a tech repair shop as soon as possible. 

Final Thoughts

Unfortunately, for those of us who are not as well versed in electronics, this is kind of a hard problem to fix.

Luckily, repairing a battery or having a converter fixed or replaced isn’t going to completely break the bank, and if it needs to be done anyway, it is a worthwhile investment.

So diagnose the issue and get that thing fixed as soon as possible. That way, you’ll be back on the road in no time, and hopefully, your lights will stay dim when you want them dim, and bright when you want them bright. 

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