I was under the impression that you could turn the headlight on and off by grounding or ungrounding pin 4 of the 12-pin header. It is always on, even with nothing plugged into the header and completely ignores what I do to pin 4. Whichever end I count 4 from. Of course, I never wanted to turn it off before. This is a 10-year-old loco with many miles on it.
Well, maybe I’ll take the “fish guts” approach and wire the silly headlight the way I want it wired