After numerous years in the Recreational Vehicle industry, we believe that our 12-pin wiring layout for the tow plug is the best solution for the vast majority of people.
Attached is a copy of the detailed wiring instructions and layouts for your 12-pin plug. These instructions are intended for printing and giving to your Auto Electrician installing the 12-pin socket on your car, so they have a hard copy of what is required.
Most commonly, we get asked for help with the requirements of DC-DC charging and the fridge connections.
Many DC-DC chargers are not compatible with Battery Management Systems, including the BMPRO range. There are ways some of these can be made functional, and there are some models which are fully compatible. Please refer to the article under 12v Section, "Do I need DC-DC charging?", for more information on this.
The Absorption fridges used in most caravans are best run directly from the alternator. We wire this way to prevent over-discharge of house batteries and help to ensure that your batteries are at their peak charge when you get to your campsite.
If you have an automatic fridge, pin 12 must be connected to an ignition source.
If you have a manual fridge, it's strongly recommended that you use an ignition switched isolator on the fridge line. This isolator is not required for automatic refrigerators as they have this function built-in internally.
Should you or your auto electrician have any questions, do not hesitate to contact us for clarification on anything.