ESU Sound Decoder GWR Railcar - ESU sound decoder and speaker

We recommend that both decoder and speaker are fitted in the tender due to space (please remember decoders can get hot) and sound considerations. Four wires will need to be run through to the loco for pick-ups and we would recommend a connector so that the loco and tender can be separated.
Below is a list of the Function keys and their assignments applicable to this model.