Whistle button on ZW Transformers

[Hotrod]

If you are familiar with Lionel's old ZW transformers, you know there's a whistle and direction change "button".  I have 2 ZW's which are both 40-50 years old yet still crank out the volts, however a while back on one transformer,  the whistle lever stopped activating sound on any of my engines. Despite being a flop with electronics, I opened the transformer shell case to determine if there was something simple and visibly wrong such as a loose wire or soulder point. But everything looked ok, so my question is where could the problem and solution be to help make my choo choo's sing again.

Thanks,

Rod in CT

[TrainLarry]

More than likely the round, copper rectifier disc needs to be replaced. It produces the DC voltage needed to energize the whistle (and horn) relays. They go bad, and can be replaced quite easily. Part # 1041-13 available here.

Larry

[Dave632]

Yes, I had to change mine.

That old disc rectifier gave me a laugh as I had never seen any like that.

I am so used to the much smaller ones that are used today.

[rrlineman]

try cleaning the copper slide arms and copper contact buttons 1st with some contact cleaner or the carboard file sticks women use for their nails. have found over the years they get pitted and carbon from the rollers get on them. if it doesn't work after that, then by all means replace the diode disc. I used the stud rectifiers rated at least 50 PIV with a 10 amp rating. hope this helps.

[phillyreading]

If you are not that good with electronics you can get the Lionel whistle button that you add on between the transformer and the track. Not sure of the part number but it might be 5609.

[BigAl 956]

Those old 1940 style rectifier discs are usually the culprit here. I prefer to pull them out and replace with a modern stud rectifier. Try a 1N1183R as a replacement. It will fit cleanly into the hole the old disk mounted to and will perform much better at blowing the whistle.