Reply to "Convert my MTH Dash-8 to DCC"

I would hope that track power isn't going through that line. It's like a 28 guage or smaller wire, and it's LONG. This likely must only be a signal wire on the micro which is just a check at startup specifying which state machine to enable (DCS or DCC). For something like that, 300ma would be about right, and I would guess actual is 20ma at 3.3 or 5 volts depending on micro operating voltage.