I have installed a TCS M4 decoder in a locomotive and reset it to factory defaults. I am only using the motor control and the white/yellow headlight wires.
I have the blue wire connected to both anodes of the LEDs and the white to one cathode and the yellow to the other cathode. The LED connected to the white switches on and off when using the appropriate function, the LED connected to yellow is on all the time, even if headlights are selected off.
I have reset the M4 to factory defaults several times, it still happens. I have tried a different controller and it still happens.
I have wired all my other decoders in this fashion, using the blue wire as a "bus" for the lights and using the function wire with resistors for the individual lights.
Some suggestions please?