M38 Early Autolite Horn

[Umassjeepster]

I have an early Autolite horn that I bought that doesn't work. It looks like a capacitor on the inside has blown up. Do they sell just the capacitors and/or the guts or is there a workaround?

 

[Umassjeepster]

Here are some photos of the horn. You can see the top off the capacitor in the second photo on the bottom.

 

[NDT]

Welcome. The purpose of the capacitor is to suppress radio interference. It is optional. Your horn could have a burned out coil, but most likely the contacts and other moving parts are corroded. See if you can bead blast it and ohm out the coil and report back.

 

[Umassjeepster]

UPDATE:

I opened up the guts of the horn and found that the coil was burnt up.


After some digging on the internet I found that you could make our own coil for the electromagnet so I went to work making one with the same size magnet wire. I was able to wrap it by making a jig and using the lathe on slow. Then, cut some new insulating pieces out of Formex on the laser printer at work. I also wrapped the inside of the horn piece with an insulating tape we had.


After some back and forth with fitting the coil back in and making sure it was sitting flat i got the horn to make some noise.

Does anyone know how this horn is supposed to sound like? It make a low pitch horn noise and it's not terribly loud.

If I had to do this again (and I might do it anyways at a later date) I would take more time to build a better bobbin to wind the coil up with. But honestly, I didn't think that I was going to be able to get the horn working again.

Sorry, it was getting late and I didn't take photos of it when it was put back together.