I have tested three Lionel tenders on my layout. I run them on an oval of track with a ZW transformer. When I throw the throttle to start the steam loco (a postwar #736 or 685), the whistle relay activates, continuously sounding the whistle as the train operates. Is this a transformer issue or a tender issue. The whistle should operate only when pushing the whistle button, not the throttle.
Thank you for your assistance,