Caravan 12V checks before your next trip

Before you leave: checks you can do yourself

• Charge the house battery fully at home and see whether it holds charge overnight with everything switched off.
• Run the fridge, lights, water pump and any inverter on 12V for a while and watch how quickly voltage falls on the display or monitor.
• Inspect battery terminals and visible cabling for corrosion, chafing, loose clamps or connections you can wiggle by hand.
• Check the solar panels are clean and undamaged, and that the regulator display shows charging in daylight.
• Test every interior and exterior light, including annexe lights and reading lamps.
• Check the trailer plug and socket for bent pins, corrosion, moisture and a firm fit, and that the cable is not stretched or rubbing.
• With a helper, confirm tail lights, indicators, brake lights and reverse lights on the van all respond to the tow vehicle.
• Test the breakaway system operation as described in your handbook, and confirm the electric brakes engage smoothly under the controller.
• Carry the basics: a spare fuse kit, a torch, and a note of where your isolator switches and fuse panels are.

Warning signs worth acting on before a trip

• A house battery that reads fine at rest but collapses under a modest load.
• Voltage that drops sharply as soon as the fridge or pump starts.
• Solar that produces far less than it used to in similar conditions.
• Lights that flicker, dim or work only sometimes.
• Fuses that blow repeatedly, or breakers that trip.
• Any smell of hot plastic, discoloured connectors, or warm cabling.
• Brakes that grab, feel weak, or do not respond consistently to the controller.

Work for a qualified auto electrician

Caravan 12V systems are more involved than they look. Undersized cable, poor earths and mismatched charging equipment cause faults that are hard to find and can be a genuine fire risk.

• Battery testing, replacement and correct sizing for how you actually travel.
• DC-DC chargers, mains chargers and battery management setup and fault finding.
• Solar installation and integration with existing charging equipment and regulators.
• Cable sizing, fusing, isolation and protection to suit the loads and runs.
• 12V lighting, accessory circuits, fridges, pumps and inverter wiring.
• Brake controller wiring, towing electrical faults and trailer plug rewiring.
• Diagnosing intermittent faults, voltage drop and corrosion problems through the loom.

A sensible service habit

Vans spend long periods parked, then get shaken over corrugations for weeks. Connections loosen, moisture gets in and batteries age quietly. Having the 12V system checked over before a big trip, rather than after a problem appears, is far cheaper than a recovery or a ruined fridge full of food.