Where Does the 12-Volt Accessory Circuit from Trailer Connector Attach on the Trailer

Question:

Where is the 12-volt hot line from the tow vehicle 1:00 in tow-vehicle receptacle supposed to connect inside the trailer itself?

asked by: Gene M

Expert Reply:

Typically, the 12-volt accessory circuit is used to maintain a trailer-mounted battery. The circuit will not charge a dead battery, but the amperage on the circuit is sufficient to maintain a fully charged battery. The 12-volt circuit would connect to the positive terminal of the battery on the trailer. The negative terminal of the battery on the trailer would be grounded to the trailer frame.

On most vehicles, the 12-volt accessory circuit will remain live even if the vehicle ignition is switched off. It is a good idea to unplug the trailer connector from the vehicle when the motor on the tow vehicle is not running. To prevent the battery on the tow vehicle from being discharged if you forget to unplug the trailer, a battery isolator like part # PK5231201 would be a good investment.

expert reply by: Mike L