Is the Auxiliary 7-Way 12 Volt Power Circuit Supposed to Turn Off with Vehicle

Question:

Does the auxiliary 12V circuit on the 7-pin trailer connector turn off when the two vehicle is parked and not running?

asked by: Paul R

Expert Reply:

In regards to a 7-way trailer connector like the 4 to 7-Way with 4-Way Adapter part # ETBC7, the black wire is a battery charge line which takes current from the vehicle's battery and applies it to the trailer. The circuit can be either keyed or constant. If it's keyed that means it will turn on and off with the vehicle or if it's constant it will be active all the time whether the vehicle is on or off. If the battery charge line is run directly to the battery then it would be constant but if it's run through a remote turn on circuit then it's keyed. This will vary from vehicle to vehicle depending on how it's wired.

Please note, even if the battery charge line is on at all times it will not drain the vehicle battery unless the trailer is hooked up. If you want to leave the trailer hooked up and not have to worry about a dead battery you can install a smart device that will cut power if the vehicle battery gets too low, the Redarc Smart Start Load Disconnect part # 331-SBI12-BLD.

expert reply by: Conner L