Troubleshooting One Wheel Locking Up When Braking

Question:

Hello, i have a 2001 f250 super duty and a 16ft custom dual axle trailer. I had the left side rear axle tire lock up on me today, while the others were working fine. I just had the trailer connectors replaced on my truck, and the trailer connector seems corrosion free. I bought the trailer used and the wires are worn and exposed, including yellow being completely worn through, however i do not have a blue wire in it anywhere, which ive been led to believe is usually brakes. I have 6 wires, black, brown, white, yellow, red and green. Im also inclined to believe it has to do with the wires and touching something else, as when i turned the tune down on the brake controller is stayed locked up.Any ideas or suggestions?

asked by: Jay M

Expert Reply:

There could be a few things that could be causing the wheel on your trailer to lock up when braking. The most likely cause would be the brake assembly is out of adjustment. When adjusted correctly, you should be only a light drag on the wheels when activated by hand.

If your brakes seem to be adjusted correctly, then you would need to check the trailer brake wiring. I see that you that you are having trouble finding your trailer's electric brake wires.

Whoever originally wired your trailer may have used a different color wire than the typical blue wire that indicates brakes. Pull the wheel and drum of the wheel that is locking-up and inspect the brake magnet wires as that come off the back of the assembly. Using a tester like # PTW2993 check to see which of the two wires has power when the brake controller is activated.

Once you have found the power wire, the other will be the ground, you will need to follow both wires along the trailer and inspect for damage that could be causing a short. If you find damaged wire you can use # 10-1-1 and # DW05745-10 connectors to repair the wire.

If all the brake wiring has been inspected and checks out to be good, then the issue may be in the brake magnet on that wheel. I linked an article that explains how to test your magnets for defect. I recommend using a volt meter or multi-meter like # PT89ZR for this test.