There was a bulletin to the Authorized MTH Service Centers, applying to the PS3 locos, but it probably applies to any with a wireless tether. Take the shell off the loco, and loosen the screws that hold the wire harness near the tether plug, and give it enough slack so that the plug turns freely. Do the same for the tender part of the equation, making sure that the tender plug can turn freely. Jeff Strank put out the bulletin last week, so most MTH service centers can do this for you if you feel reluctant to tackle it yourself. Me included.