Troubleshooting Trailer Brakes After Installing a New 7-Way Trailer Connector

Question:

I did all the wiring as you showed in the video but I dont have electric brakes, does the Aux. breaks cable have some thing to do with my problem? if so where do I connect the aux. brake cable or where does goes to?

asked by: John J

Expert Reply:

As long as your 7-way trailer connector was wired as shown in the attached diagram, the auxiliary power wire should not have any affect on the electric brake output wire. The first step I would take is to test the vehicle side 7-way socket to make sure power is reaching the trailer connector.

Using a circuit tester like part # PTW2993, test the pin in the 5 o'clock position (see photo) on the vehicle side 7-way. Apply the manual override on your brake controller to send power back to that pin. This is a fairly simple step, and it will tell us that power is definitely reaching the trailer. If you do not have power on the vehicle side 7-way, then you could have a blown fuse, if the brake controller and trailer wiring is OEM, or there is a problem with the brake controller or brake controller wiring.

If power is reaching the trailer connector, then you could have a ground issue. Make sure the ground for the trailer connector and the grounds for the brake magnets are attached to a clean bare metal surface of the trailer frame and free of corrosion. I also recommend inspecting the electric brake wire going from the trailer connector to the brakes. Look for any areas that could be pinched, frayed or damaged that could cause a short.

If the wiring is in good shape and the ground are clean, listen for a slight hum at the trailer hubs when the manual override is applied on the brake controller. If you hear a hum, that would indicate power is reaching the brake magnets. Power could still be reaching the brake magnets without a humming sound. If the brakes do not work still, I recommend removing the wheel and hub and inspecting the brake shoes and brake magnet.

If you can see the copper windings on the face of the brake magnet, that would indicate that the brake magnet will need to be replaced. The brake shoes may also need to be adjusted if they are older brake assemblies or brand new brake assemblies that have not been adjusted. I have attached a help article on how to test trailer brake magnets. I have also attached a trailer brake installation video for you to check out.

expert reply by: John H