This question applys to the Bachmanm On30, 4-6-0 locomotive. In removing the boiler for painting and weathering, I disconnected the LED headlight. Like most LEDs It has a long and a short lead. If I am correct the long lead is the positive and the short is negative. The plug-in connector as a yellow wire and a brown wire. How should I orient the plug when I plug it back onto the LED? Which wire goes to which iead? I believe that LEDs are polarity sensitive. Am I correct?
Yes they are , so if you connect the wrong way the LED won't work.
50/50 chance you do it right. ;D
You won't distroy the LED because it is a diode and works only one way.
If you use an aftermarket decoder be shure there is a resistor in the + line.
Take a 560 Ohm resistor (green, blue , brown).
If you think the light is to bright a 1K resistor also works fine (brown, black, red).
Ton