I need help with snail-shell horns

[mshaver51]

Friends,

I have one operative snail-shell horn, and one non-operative horn, so I'm seeking wisdom (to make the inoperable one functional)...

As the photos show, the removal of the cheese-head screws appears to divide the snail-shell horn into 3 sub-assemblies. There appears to be a very thin paper gasket on both sides of the diaphragm, which leads to the first question --

How thick is the paper gasket? (And does anyone have a source suggestion?)

The diaphragm appears to be painted on the side opposite the vibrator, which is simple enough, but upon removal, the diaphragm is not actually flat (although it gets flattened when the parts are assembled).

I have dis-assembled and cleaned it only to the 3 sub-assemblies at this point, which leads to the last and broader question(s)...

What kind of tests do I perform?

Is there any part that normally fails? what do you recommend (including magical incantation) that will bring it back to life?

[xpensivewino]

I just rebuilt both of mine, and neither were working. Just clean everything well. The paper gasket I just cut out of a waxy paper, like letter paper thickness. The area that was causing mine not to work was the small set of points that you see in the left hand half in your photo. I took a very fine piece of 600 grit sand paper and worked it in between the points and gave them a good cleaning. They tend to get dirty as well as stuck together. Once you have them loosened and cleaned, use a voltmeter to check for continuity through the copper windings. You will need to re-assemble the horn to test unfortunately, but this takes very little time. Once assembled, I just apply 12 volts to the spade connectors and they should beep. They are loud, so don't do it in the kitchen like I did !! I hope this helps.

[mshaver51]

these are good suggestions. I will try them. Thank you.

[Churchill]

I just went through this on my '70T restoration. What I thought was a bad horn was actually just spade connectors (both male and female) that had 46 years of road crud built up on them because they sit unprotected in the wheel wells. Clean those connectors while you're in there.

[mshaver51]

special thanks to xpensivewino. i had not noted the 'points,' but cleaned them off, and am using waxed paper for the gaskets.

will try to re-assemble the horns this weekend and will let you know if it worked.

[xpensivewino]

No problem..I really hope it works for you. It sounds silly sometimes to save some of these bits from the trash, but to resurrect the original horns that came on the car, and hear them beep again was such a tonic for me. That's what restoration should be about, not just buying shiny new replacement parts. Best of luck! Steve