I have a MTH locomotive - a Santa Fe Diesel A-B-A, with a powered A unit, and unpowered trailing B and A units. The powered A unit is numbered "16" and the unpowered A unit is numbered "17".
I have no idea what the model number is or what the vintage is.
It has two vertical electrical motors, a speaker, lots of wiring, electronic devices and circuit boards.
I dont know how to use it. When I put on the rails, and turn on my vintage Lionel 1033 transformer and crank up the voltage, the lights come on, the locomotive's speaker blasts out the sounds of a diesel engine along with other sound effects - but it wont move either forward or backward. There is a little switch underneath with forward and reverse arrows - and this switch doesn't seem to make this locomotive go in either direction.
This is the newest locomotive I've ever owned - all of my other locomotives are 50 years old and older.
Here are some pictures: