Brakes not working, Help troubleshooting

Usually you can hear the magnets hum if they are getting current. Check the wiring connections under the trailer near the wheels. You will probably have to remove the electrical tape from the connection first. The wiring will go to one front brake first, then in another wire that goes through the axle, out the other side then into the brake. Another wire will go to the rear wheel, then through the axle like the front one did. A common problem is the wire inside the axle. It can become worn and short out the brake. I just run a wire on the outside of the axle instead of replacing it inside the axle. Secure it to the axle with wire ties. You will have to remove the hubs to check the wiring on the magnets. Many times this wire will break off the magnet. This will require new magnets to fix this. After removing the hub you can pull the break away cable and place a wrench against the magnet to see if it is working.