[laverdur]

This sounds a lot like what I experienced when the brake wires inside the axles became chaffed and the metal conductor was shorting out against the metal axle tube. It took me a long time to figure this out due to its intermittent nature and inability to duplicate when stopped. Solution: disconnect the brakes from the wires that go through the axle tubes and zip tie new wires to the outside of the axle tubes. Be sure to use a proper wire gauge that will carry the current the brakes need. You can make a cleaner installation by getting a couple strips of plastic wire mold at a home improvement center and zip tying those to the axles to act as cable messenger.