Someone mentioned that they replaced the #12 wire from the brake controller to the trailer. Before the repair, the best voltage they would get at the brakes was only about 8 volts and about 2 amps per brake.
After changing to #10 wire, they where able to get 3 amps to each brake, and 18 amps total to all three axles. It could have also been a poor electrical connection, and the new wires solved that problem as well.
If the trailer is more than 10 years old, improved wiring is the first step that I would take. Then inspection, lube everything, and proper adjustment of the brakes should solve the problems.
You basically eliminated a brake controller problem because the trailer brakes perform bad on two trucks.
Also with the brakes on, take a compos around to all the tires. it should point toward the magnet, not north when the brakes are applied. Do not apply the brakes to long, as you can overheat the magnets. If your truck is not there, just pull the plug on the break-away switch, and put it back in. The converter and battery will supply full 12 volt power to each brake while the plug is out.
Good luck!
Fred.
