12 Pin Trailer Plugs & Sockets
What the 12 pin flat gives you
The 12 pin flat is the usual fitment on Australian caravans. It is a straight extension of the 7 pin flat: pins 1 to 7 carry exactly the same circuits in exactly the same order, with a second row of five above them. That means a 7 pin flat plug will fit a 12 pin flat socket and the lighting circuits will work normally, you simply do not get the extra five.
The five extra circuits are pin 8 battery charger or winch, pin 9 auxiliary or battery lead, pin 10 a second earth, pin 11 rear fog light and pin 12 auxiliary. Cable colours and the full pin assignment are set out in our trailer plug wiring diagrams guide.
One thing worth knowing before you rely on pin 8: a 12 pin connector is fine for a trickle charge, but it is not the right way to run a serious charge circuit to a caravan battery. Most setups run the 12 pin for lighting and auxiliaries and a separate Anderson connector for the charge line, because that is what carries the current without voltage drop.
Related categories
- 7 pin plugs and sockets in flat, small round, large round and heavy duty, still the most common trailer fitment
- Anderson connectors the correct connector for a caravan charge line
- Adaptors and leads including 7 pin to 12 pin adaptors for when the car and van do not match
Parts for a caravan wiring job
- Junction boxes to keep the joins sealed and serviceable
- 6 B&S cable for the charge line, sized to keep voltage drop down
- Cable lugs for battery and earth terminations
- Dual battery wiring for the rest of the charge circuit
- Clearance lights required on caravans and wider trailers
- Breakaway systems the separate emergency brake circuit
Guides
- Australian trailer plug wiring diagrams covering all twelve pins with cable colours
- Installing a dual battery system how the van battery gets charged
- DC-DC charger guide why a charge line needs more than a 12 pin
- Caravan solar panel installation the other half of a touring power setup
- Caravan power inverters for running 240V appliances off the van battery
