Troubleshooting Electric Trailer Brake Seizing Up After Backing Up  

Question:

Expert Reply:

This is an odd situation because it is difficult to determine if the issue is electrical or mechanical in nature. I recommend starting by checking the wire to your electric brakes using a circuit tester like # PTW2993. If you are getting constant power to that brake magnet, then I recommend thoroughly cleaning your connection between your vehicle and the trailer plug using sand paper or steel wool because another function may be sending power due to corrosion or debris. Then reconnect the trailer to the vehicle and test that brake wire by the magnet again if the problem is resolved, then put some dielectric grease # 11755 between the connections on your vehicle and trailer plug to keep moisture and debris out of your connection.

If it is not solved, then I recommend testing the functions of each pin on your vehicle side connector when the trailer is not connected using the circuit tester. If that checks out, then you know there is a trailer issue. If not, you will need to figure out the trailer wiring on the vehicle side first.

If the vehicle checks out, plug the trailer back in and then trace that brake controller output wire testing every few feet for power. Use the manual override on your brake controller to test as needed. You should get power when the override is activated and nothing when it is not engaged. If you find a short, replace the wire using # 12-1-1. Make sure your brake magnet has a solid ground connection on bare metal that is free of corrosion or debris.

Next, bench test your brake magnets to see if they need replaced. I've attached and article to assist and you will need a multimeter like # PT89ZR. If your magnets need replaced, I recommend simply replacing the entire assembly.

It sounds like it could alternatively be mechanical with a warped armature. Replacing the assembly would also solve that issue.

expert reply by: Jason S

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