Just to nail the version of the loco you have, 1st generation, 2nd and 3rd with DCC fitted sound, could you post a picture ? Are you running it track power, DC or DCC, or even with battery ? Is the sound card one supplied originally with the loco by the manufacturer (fitted directly, with pins to the loco's main PCB) or an aftermarket one ? With this information we can possibly direct you to possible solutions to your problem and the correct wiriing diagrams for the loco. Max
Quick thought, are the switches, under the sand boxes, at the rear of the bunker, if fitted, set correctly for the mode of operation you are using. I am assuming here that you have the 3rd generation model fitted with a factory fitted sound card that can operate in both DC & DCC mode.