postwar horn not working

I can't tell for sure, your second clip is really distorted. Is the armature canted off to the left instead of centered above the magnet? When you touch the test leads to the frame of the horn and top of the armature does it vibrate? If not the most likely cause is a bad ground on the coil. It can be sometimes fixed with a fine blade screwdriver between the coil wire and top of the coil magnet. 

thank you. I'll try that and report back later!

Disconnect the horn wire from the relay. Take out the battery. Touch the bottom of the battery directly on the horn and touch the horn wire to the top of the battery. The horn should sound. Adjust the screw on the horn for proper sound. If the horn does not work this way, it needs replacing.

Larry

Thanks Larry. I’ll try that and let you know. Sounds like an easy test. 

Here's a video clip of trainlarry's test. Not a sound..but if it does have a bad ground, I'm guessing that could be why SO, ChuckSartor, you there? here's a better clip of the horn's insides. You're asking if a wire in that little coil could be touching? I can/should unwrap the paper and look for a coil wire touching?    A new horn is certainly simple to order, I am just hoping a simple adjustment would fix it. 

Videos to help

thanks, Mike

If you want to go through the trouble.........remove horn from loco while you have the top off. Using you transformer, not battery, set to low voltage. One test lead to the wire of the horn, and the other lead touch the flapping arm of the vibrator. It should spark and buzz, letting you know the coil is good. If nothing, use the test lead wrapped around a thin blade screwdriver and poke between the top of the windings and the iron slug on top of the magnet. This is where the other winding to the coil usually is. When you find the 'sweet spot' and the armature vibrates and a drop of solder at the location. The solder won't stick to the iron slug, but if you can find the other end of the wire it will connect the wire enough to power the coil. Then reassemble holding the top piece, not rebending the tabs just yet and check with a battery. It should honk now.

Thank you for all your help guys. This discussion board is a blessing for me. I understand too little and not enough so it's great to come here even just to ask a question.   

  I disconnected the horn completely from the engine. Ran two wires from the transformer. One on the horn body, the other to probe on the nipple of the vibrating bar and, also, I peeled the paper off the little coil and touched in and around the coil for a while and nothing. So, I have to go with the coil is somehow bad and I'll order a new horn (and other goodies while I'm at it.  Thanks for the help, I now learned a little about troubleshooting.

To follow up.    Horn didn't work. relay on engine rises and falls as expected. no hum, click, or spark from horn at any time. tested using battery, tested straight from transformer nothing. No spark, hum or movement from horn. The engine is -new to me so horn never worked.  solution for me, new horn.

Those PW horns are essentially the old bicycle horns from the 1950's which I had on my "heavyweight" Columbia bike.