Knowledge is power

Knowledge is power with advice from the Technical Manager, Martin Spencer on looking after your electrics

Attitudes towards leisure vehicle habitation electrics vary among owners. To some, they’re a mystery that defies explanation. To others, they’re a frustration to tinker with, despite a dangerous lack of actual knowledge.

Most people are between those extremes. This article is not intended to make you an electrical expert, nor encourage any effort to repair when you should really be seeking professional assistance. It might just help avoid some problems while on holiday, however.

Prevention is better than cure

When your leisure vehicle was first built, its electrical installations should have been certified as being functional and safe, in exactly the same way (and to the same regulations) as those in your house would be. If it’s also certified by the National Caravan Council through their Manufacturer Approval Scheme, you can be sure that the 12V electrics additionally comply with the extra details covered by the relevant British and European Standard – non-NCC approved vehicles don’t necessarily follow this guidance. An annual habitation service should check the basic functionality and safety of the electrical systems, but after a few years’ use, the installation could have hidden wear and tear, perhaps from general use, aging of components or as a result of being shaken around on the road. It’s recommended that periodically (notionally every three years, compared to ten years for your house) you should have a more stringent electrical check, therefore, namely an ‘Electrical Installation Condition Report’, which checks the condition of components and wiring in much more depth. This can be done by a competent electrician, or by suitably trained service agents, such as members of the Approved Workshop Scheme. Do be aware that this detailed check will be quite expensive, however – it typically takes four hours and we’ve seen prices quoted from £150 to over £300.

Even with good professional attention, it’s prudent to keep an eye on the condition of key parts yourself. Look for damage or deterioration to your mains hook up lead and its plugs, the mains input socket to your vehicle and the mains and 12V sockets within the vehicle. Are switches stiff or do lights flicker or intermittently stop working? Get these issues fixed before you travel.

Be prepared

Some minor faults can be safely diagnosed and rectified while you’re away, but you may need some reference material and basic tools. Your handbook should indicate where fuses and circuit breakers are (and include a full circuit diagram, if you’re lucky) but some are better than others at this, so spend a few minutes investigating and familiarising yourself with the location of key components, in case you end up having to look for them in the dark. If you don’t have a handbook for an older vehicle, check the manufacturer’s website to see if copies can be downloaded, or the website www.manualslib.com might have one. Owners clubs for specific makes can sometimes help, or ask on a web forum like Club Together and another owner might be willing to scan the relevant pages. Better handbooks contain fault checking advice. The installation and use booklets for specific appliances (e.g. fridges) might also have such information. If you don’t have those, they can often be downloaded from the relevant manufacturer’s website.

A small kit of tools and spare parts is useful:

• Screwdrivers – flat head and cross-point, including small ones for cable connectors
• Long-nosed pliers
• Knife or wire strippers for trimming insulation
• Insulation tape
• Some abrasive wet & dry paper for cleaning connectors – a disposable nail file can also be useful for this
• Head torch – handy if wiring or fuses are buried in the depths of a locker…or if the lights have failed!
• Plug-in mains socket tester – the kind with lights that indicate a range of faults
• A basic multi-meter – particularly to check 12V system using the voltage measurement or to check for continuity (i.e. no break in a circuit) using the resistance measurement
• Replacement mains and 12V fuses in various ratings
• Spare light bulbs
• Perhaps spare 12V plugs – the ‘cigar lighter’ type ones can be quite vulnerable to breaking

If touring abroad, when UK-specific parts are going to be hard to source, it might be worthwhile adding a spare UK mains plug to that list. Also, given their likelihood of failure, a spare submersible water pump (if your outfit uses one) is a good precaution, although the more complex types of these can be quite expensive. Well worthwhile, though, if you have an older outfit with a cheap, basic pump.

As a generalisation, if faults occur within an appliance like a fridge, or a unit like a battery charger, it’s quite unlikely that you’ll be able to do much about it yourself, unless you have a lot more technical knowledge than most owners. Where the issue is to do with wiring, connections and such like, there’s more chance of it being a simple fix, however.

Some specific mains issues:

• If nothing is working, check if there is power at a mains socket (using the plug-in tester), check the mains switch/RCD on the fuse box has not tripped, that the mains connection cable is plugged in and undamaged and that the site power supply is activated.
• The mains connection cable is particularly vulnerable. Unplug the cable before checking it! Visually check the whole length of the cable looking for cuts or splits in the insulation. Check plugs for damage to the pins or tubes or any signs of overheating. Make sure the cable has not been pulled partially out of the plugs. You can check the continuity of each connection using the resistance measurement function of a multi-meter – any connection indicating maximum resistance (often displayed as ‘OL’ or over limit on digital meters) has a break in the cable or a connection problem in a plug. If a wire has come loose in a plug and there’s no other damage, it can be reconnected. If the cable itself is locally damaged, you could shorten it and only use the ‘good’ part as an emergency fix (replace with a full-length cable as soon as possible). If removing and refitting a plug, photograph the correct wire positions with your phone before disconnecting them. If plugs are damaged, though, replace them.
• If some appliances or sockets work but others do not, check fuses and miniature circuit breakers, or there could be joins in the wiring loom where connectors can come loose. If fuses blow or MCBs trip repeatedly, there’s a fundamental fault – don’t ignore that and have the reason investigated.
• Use your senses – if something feels unduly hot, gives off a burning smell, buzzes or crackles or you see a wisp of smoke, then something is wrong. Switch it off and don’t use it again until it has been checked.
• Note that some modern mains-powered appliances (e.g. fridges and heating systems) may require a 12V power supply for their control circuits, so you might need to check 12V fuses etc. too.
• Modern appliances will often indicate fault codes via a numerical display or sometimes a series of beeps, which can be useful to identify a fault (as long as you have the handbook to interpret the codes or can find a helpful website). This might not always enable you to fix the issue, but can be useful when seeking professional assistance, as the codes may indicate which spare parts a service agent will need, meaning one visit rather than two.

Some specific 12V issues:

• 12V circuits are much safer to deal with than mains ones, but don’t assume they’re without risk. This is particularly the case when dealing with batteries and battery charging circuits. As a rule of thumb, treat anything with thicker than normal wires with extra caution.
• Unlike mains circuits, which usually follow standardised colour codes, 12V wiring may use every colour of the rainbow, sometimes with no apparent consistency even within one vehicle. A manufacturer’s wiring diagram might help, or might not. If removing and replacing anything, a quick photo with your phone can be really valuable to make sure everything goes back correctly.
• Push-fit connectors are commonplace…and commonly displaced. Even if apparently securely fitted, the act of unplugging and then plugging back in can sometimes fix a fault by reseating a connection, or by cleaning a dirty/corroded contact.
• While mains fuses are sometimes positioned with a degree of creativity, the location of 12V ones sometimes appears to be wilfully obscure. A wiring diagram may show whether there is a fuse in a circuit, but some searching may still be required to work out where on Earth it is.
• 12V wiring can be very flimsy, and thus particularly vulnerable to wear and tear due to road vibrations and such like. Wires can break off from where they should be attached, or fray perhaps where they pass through a hole in a panel. Finding such faults can be hugely time-consuming and frustrating. Good construction will use cable clips and strain relief to minimise issues, but not all wiring is done to the highest standards.

Safety first

If you are at all unsure about an electrical problem, don’t risk it. Call in professional help. It’s better to struggle with something not working than it is to risk more damage or your safety by either continuing to use it or trying to fix it without adequate knowledge.