How To Identify RV Lights Issues?
Lighting can be one of those annoying and niggling issues in most caravans regardless of whether it’s old or freshly off the lot from a dealer.
Question: We have purchased a second-hand van that is at least 15 years old, and we keep having issues with lights not working — do I need to go to LED’s and refit the entire van? (from Paul Essary)
Answer (David Bayliss): Hi Paul. Lighting can certainly be one of those annoying and niggling issues in most caravans regardless of whether it’s old or freshly off the lot from a dealer. The fact your van has a bit of age on it should not be the issue. Instead, it is most likely you will need to check and maintain a few simple things to get them working. Unfortunately, they have not yet made a caravan that is maintenance free!
It is unlikely you need to move to LEDs, as the issue will most likely be with in your wiring somewhere. While that sounds daunting with all that black cabling running through the van, it’s probably not! It is reasonable to expect that the lights on your van having been working fine for the previous owner. A few basic tools, a multimeter and some sandpaper and your lights will no longer be an annoying hassle.
While older style bulb globes with the filament inside are becoming a thing of the past, there’s no need to replace them unless you have issues with how much power they draw from the battery. They are certainly not as power efficient as the new Light Emitting Diodes (LEDs). We have often heard, “the bulb globes rattle loose and don’t have a good connection,” but this is unlikely as the wire contacts inside don’t weaken over time. It’s more common that the globe is old and needs replacing or there’s a connection issue.
The most common of reasons why lights, inside or out, are not working or are intermittent, is that there is not a good ground for the electrical circuit. The caravan chassis, which is made of steel, will have been wired as the electrical ground for the 12V circuitry. The cabling from the trailer plug at the back of your vehicle will contain an earth return wire and this will, in most wiring setups, be wired directly to a clean metal ground point on the chassis.
The first step is to eliminate a damaged cable. The three main causes of a damaged cable are firstly the copper wire has become exposed as it has been scraped by something, or that it may have been penetrated by a screw or staple. Check all wiring if possible, to identify if this may be an issue. For example, if a staple or screw has inadvertently gone through wiring, it creates a short circuit (the path of least resistance) and your lights will not work. The third potential cause for concern in your wiring is broken connectors which join wires. Where there are identifiable connectors gently see if any of the wires pull away from either side.
Next steps are to identify if there is a grounding issue. Your lights will need to be grounded back to the chassis. This will be either through a wire from the lighting circuit back to metal connected to the chassis or it will be a return earth wire. If you have checked all possible wiring looms as previously, it is unlikely to be the earth return wire and more likely that as your van has a little age on it, a degree of corrosion has crept in on the earthing point. This corrosion will prevent a good electrical connection and show itself as faulty lights. The light is not faulty, just the wiring connection needs some maintenance.
Use your multimeter to identify where the breakdown in the grounding is, and then grab the sandpaper or wire brush to clean up the earth connection point. For those new to multimeters, don’t be scared. Grab an ‘el cheapo’ from a hardware or auto store and check out how to use it on YouTube. It is super easy and really is an essential part of your travelling toolkit and saves a costly trip to the auto electricians.