After Changing Brake Shoes and Adjusting Brakes, Brake Controller Does Not Fully Power Brakes

Question:

Recenty replaced electric brake shoes on 5th wheel trailer and manually adjusted each. Verified each brake electrically worked with controller manual slide while parked. Followed instructions in manual to set controller. Boost on b3 and having to set it on 13 with brakes barely grabbing. Is there something wrong with system?

asked by: Gary

Expert Reply:

Assuming that the Prodigy brake controller, # 90185, was working before, you may want to go back and look at the brakes again. In the process of repairing the brakes, the ground for the magnets could be loose. You will also want to make sure that there is no grease in the hub on the shoes or where they contact the hub.

Also check the armature surface of the hub (where the magnets stick to the hub) for any discoloration which would indicate a problem with the hub. You can try the adjustment process again. Adjust the brakes to the point where you cannot move the trailer wheel. Then back it off until the wheels spins but you hear a slight constant drag from the shoes.

Take a look at the magnets. If you can see the windings coming through then they will need to be replaced. To further test the magnets you can follow the steps in the FAQ article I have linked for you.

You can also check the vehicle and trailer side connectors for corrosion. Corrosion can build up on the pins and behind the connectors where the wires attach.

To test the controller, cut the blue wire a few inches back from the rear of the controller. Fully apply the manual override. The blue wire should show the proper voltage when testing it with a multimeter like # BTMT15. If there is little or no voltage, that indicates a problem inside the controller and it will need to be replaced.

If the voltage is correct, reattach the blue wire. Check the connection on the red wire. If the problem only happens with the brake pedal and not the manual override then that could mean a poor or lost connection on the red wire. If the red wire is hardwired into the brake switch wire, check the connection. You can also check the stop light fuse on the truck to see if it is blown if the controller is hardwired or plugged into a port.

If everything checks out and is working properly, be sure to set up the controller with the boost off. Also make sure that the controller is mounted within the range specified in the instructions and that it is not tilted or turned to one side. I have included a link to the controller instructions for reference.

expert reply by: Michael H