My ZW-C fails to blow horns & whistles on about 50% of my engines/tenders. I checked the DC voltage component on the rails and found (approx) -0.25vdc while not blowing the whistle and +1.3vdc while attempting to blow it. In almost every case, when I encounter a non-blower/honker, I carry it over to my PW ZW setup and it blows just fine.
Thoughts or suggestions?
George