How to Wire Trailer 6-Pole Connector to Provide 12V Battery Charge Circuit

Updated 01/31/2018 | Published 01/30/2018

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Question:

I am replacing a 4 pin socket on vehicle side with a 6 blade socket so I can charge battery in the tow vehicle using your kit HM47054. My question is: which blades on the new six blade socket will I wire with the existing wires from the old 4 pin socket on the tow car? Also, which blades will be used to power the battery charger. Thanks for your time.

asked by: Fred S

Expert Reply:

The pin/function assignments for 6-pole and all other trailer wiring formats are shown in the help article that is linked for you. I also included a photo of 6-pole connectors detailing their common function assignments. In 6-pole connectors the 12V auxiliary power circuit is usually assigned to the center pin. But some trailers will instead be wired with the brake power circuit on this pin. It just depends on the trailer.

You can determine which wiring setup is on your trailer by applying 12V battery power to the center contact on your trailer plug (and with the ground connected too, of course). You can also just trace the wires.

The basic lighting signals for stop/turn/tail lights from your 4-pole will connect to the pins noted in the photo/article.

Please note that the 12V power feed from your vehicle 7-way will deliver enough power to maintain an already-charged battery during travel but it will not deliver enough power to re-charge a badly depleted battery. For that you want to use an AC-powered charger like the NoCo # 329-GENIUS10 battery charger.

expert reply by: Adam R