Trailer Brakes First Locked Up and Now Will Not Work After Re-Wiring 6-Way Round Trailer Connector

Question:

Wired in the initial set-up of the adapter the brakes are constantly engaged. When rewired the brakes dont work at all. 2000 Hudson trailer with 6 round pin. 2012 Dodge 1500 with 7 blade.

asked by: Mike

Expert Reply:

There are 2 ways to wire a 6-Way connector. The center pin will either be for the trailer brakes or will be the 12-volt power. When these are switched that is when you see the brakes engaging constantly. I have included a picture that shows the typical ways that a 6-Way is wired. The diagram shows the center pin with 12-volt power.

If you configure the adapter correctly to match the trailer and the brakes are still not working, then you will want to do some troubleshooting by first disconnecting the trailer. Leave the adapter in the 7-Way on the truck and use a circuit tester like # PTW2993 if needed to test the output side of the adapter.

If the brake signal is making it through to the appropriate location, then you know the issue is on the trailer side. If the signal is not making it through that could indicate a wiring problem inside the adapter. Remove the adapter and check for the proper signals on the 7-Way connector. If these signals are correct, then you know the issue is in the adpater. If the brake signal is not coming through on the 7-Way, then there is a problem further up.

Make sure that the brake controller is working properly by severing the brake output wire from the back of the controller a few inches. Use a circuit tester to test the end coming out of the controller. It should show power when you apply the manual override. If it does not, then that indicates a problem with the controller. If it does, then there is most likely a break in the wiring between the controller and the 7-Way that you will need to track down.

If everything checks out on the truck, then there is a wiring issue on the trailer side. Make sure that the connector is clean and corrosion free on the pins and in the back where the wires attach. The main trailer connector ground and the brake magnet grounds should be attached to clean and corrosion free bare metal surfaces.

You can further test the brake magnets by following the FAQ article I have linked.

expert reply by: Michael H