With all this banter back and forth, you never did post the exact product number for this engine. That's important information!
If I knew it John, I would. The engine came in a set box long ago, and the box with the product ID went away, a long time ago. As I recall it was a PS2 Chessie Construction set. Prior to that purchase, I bought a PS1 Chessie Construction set, along with a PS2 Texas Special construction set.
The sets, for the money, could not be beat. Trans brick (100 watt for the early ones) along with 8 pieces of track, 3 cars, and a PS2 engine. wires, lockon..could not be beat, for the price. It was like getting the cars OR the track for free.
As for the bulb, it is probably the switch on the bottom. The grandkid, or a friend may have hit it, I will know more when I can put hands on the engine. Thanks all again for the feedback, much appreciated!