NNJ Railfan posted:Very helpful advice, thank you. So the relay does operate when I push the whistle lever half way. However, the only sound that comes out of the horn is a very angry buzz. I turned the adjusting screw in both directions bit no difference. Time to replace the horn?
Maybe not. Try to wire the horn directly to a good battery as I explained above. The relay may have a high resistance and not allowing enough power through. If still just a buzz you can then try to shock it with 10volt AC. Horn should make more than angry buzz. It should be an Angry Beep.
Also check the battery contact points in the engine to make sure there is no corrosion or rust. Take a bright boy or fine emory paper and polish the lid where it touches the battery and do the same where the top of the battery touches. And most importantly make sure you're using a good battery.
