773 new york central lionel whistle tender won't work

hello my layouts are powered by lw 125 transformers - i bought a new whistle tender for ac current and it would not work with my built in whistle button - so i bought a sound activation button - still nothing - sat it my dc current southern express 0 track by mistake and the whistle sounds when the dc current train is in reverse - please help i bought it for my old ac current layout :frowning: thank you for your time :slight_smile:

p.s. it was brand new in the box when i got it saturday :slight_smile:

[#welcome] the-kid,

Sounds like your transformer needs repair, try revresing the wires on the sound activation switch, also the sound activation switch must be on a terminal marked A or B, not on the U or Common. Try that and it should work.

Lee F.