Trailer Brakes Lock When Plugging in 7 to 6-Way Adapter

Question:

I bought a Hopkins Wiring 7pole to 6 pole or 4 pole flat. My truck 06 Dodge 2500 has a 7-pole on the bumper, and a 4 pole flat underneath hanging. My camper trailer is a 6 pole with brakes. When I first plugged in the adapter using the 6 pole from the trailer the brakes locked up. To get home with the trailer lights working, I disconnected the brakes on the trailer. It appears the adapter/wiring is setup to charge a battery on the camper trailer, but my battery did not charge. How can I setup the wiring to charge the battery? How do I test with a multimeter that the battery is being charged. Is it possible to have brakes and charge the battery? If so, how do I wire it correctly. Thanks so much!

asked by: Cooper B

Expert Reply:

Your brake and power issues are a simple fix. The problem lies with your adapter. There are two accepted methods of wiring a 6-way connector. One method uses the center pin for the brake output, the other uses the center pin for the 12-volt accessory power feed. Apparently, your trailer is wired one way, and your adapter is wired the other. If your adapter is wired incorrectly, once the trailer is plugged in, the brake circuit is receiving the 12-volt power meant for the accessory feed and the brakes immediately lock up.

This can be repaired by rewiring the adapter, swapping the connections to those two pins or by using a Universal Adapter, like part # 47549.

Once the wires are swapped to their proper positions, you should find that everything operates correctly.

expert reply by: Mike L