How to Charge a Trailer Battery Via a 7-Way on a Trailer Towed by a 2008 Nissan Pathfinder

Question:

Nissan pathfinder 2008 7pin harness and brake ctrl installed how do I get the battery charge to work

asked by: Phil

Expert Reply:

If you are trying to maintain a charge for a trailer battery via the 7-Way, you will want to use the top right pin on the 7-Way (if looking at the front of the vehicle side plug). It is the 12 volt power source.

On the trailer side connector, attach the wire coming from the top right pin (if looking at the back of the plug) to the trailer battery positive terminal. Now when the trailer is connected and you are towing, the tow vehicle will provide a maintenance charge to the trailer battery.

If your 7-Way vehicle side is not providing 12 volt power, you will need to check that the wire going to the top left pin at the back of the plug is connected to the vehicle battery.

expert reply by: Michael H