K-line whistle help

[Anonymous]

I think I remember reading a few years ago that in older K-line engine (with horn/whistle) the horn/whistle would not sound with the standard whistle controller on lionel transformers, but needed a k-line specific controller. Does anyone know if this is correct? Can you give the details?

I aks because I have some old k-line engines that have horns/whistles and I can't seem to get the horn/whistle to work. Thanks for any help.