I would appreciate your help with a Legacy S-gauge Lionel American Flyer Gray UP Challenger that will no longer respond to Legacy commands and only runs in forward whether under Legacy or run in conventional mode with a transformer. What do you think might be wrong with it? Below is some more information about the way it performs.
In Legacy mode: When you power up the tracks to 16.5-18.0 VAC the headlight comes on as it should and the engine does not move. When you enter its ENG # (#77 in this case) on the Cab2 and move the red throttle control knob one speed step or more, or press any of the standard speed buttons including Roll, the engine takes off at a ferocious rate of speed. If you apply less power to the tracks (e.g. 5-8VAC) and follow this procedure the engine takes off less quickly and you can control its speed by varying the voltage to the tracks as if it were being run in conventional mode. When you press the direction button, the engine stops, but when you try to reverse it, the transformer humming pulses as if it is getting met with resistance and the engine fails to move. It only runs in forward. The soft Reset key and default reprogramming procedure on page 17 of the Owners Manual do not make any difference. The engine also performs this way when run with a TMCC Command Base and Cab1 instead of Legacy. It also runs this way whether the boiler shell is on the chassis or off the chassis and the chassis is run by itself.
In Conventional mode: The engine runs in forward and its speed can be controlled by how much power you apply to the tracks with the transformer. However, the engine will not run in reverse, only in forward. When you toggle power to get into reverse the transformer humming pulses and the engine does not move. The smoke unit works and can be turned off and on with the slide switch. It also runs this way whether the boiler shell is on the chassis or off the chassis and the chassis is run by itself.
Thanks in advance for your time, attention, and recommendations on what might be wrong and what I should try to do to regain full Legacy operation of this engine.