Find the reverse unit lockout switch. Get the train running forward, and lock the reverse unit in forward. Now when you blow the whistle, the train won't stop and reverse.

Larry

Welcome back to the hobby.

What you have described about the engine when the whistle is blown seems odd to me.  I have engines that are much newer than 25 years old and none of them do as you describe when the whistle button is activated.  There must be something about your engine or the ZW transformer that is causing this to happen.  Do you have another transformer?  Do you have other engines with horn or whistle?  What type of reversing unit does the engine have?  I am curious about why this is happening to your engine.  Is there an O gauge club in your area or a Lionel service store?

Larry and tfcii,

I will unlock the reverse unit and try hitting the whistle button faster and see if that helps.
Also, I joined the Lionel Collector's Club but have not been very active in it yet.  My wife has Alzheimer's so a lot of my time is taken up caring for her.  The model trains are a good diversion.

Thanks,
John H.

I have a RW transformer and the whistle button can reverse the direction, as described in the original post.
note:  my diesel engine horn is inoperative.

side story not meant to hijack thread:  as a kid, I left the D cell in engine, which leaked and corroded the electricals   I had cleaned parts, but never got horn to function.   I should research how to repair....