I am a new member to this forum, and I thank everyone who participates.  I have a post-war 2035 engine (smoke, light, e-unit) running with a  Model 6466W tender.  Both work OK, however when I activate the whistle control on my ZW transformer, the whistle will come on slowly, but the e-unit buzzes at the same time.  If I remove the engine from the track, the whistle will operate the same. Can anyone offer places to look?  Thank you for your help.