Electric Horns - Troubleshooting

Looking for a little trouble shooting help. We have dual electric horns by AFI that are nine years old. Both appear to have gone out. Pushing the button at the helm only yields a soft short sound. I checked out all wiring from the switch to the horns and everything appears tight. No corrosion anywhere. Pulled the backs off both horns and everything looks clean and tight. Any ideas? Thank you

John T.
N3522
La Tempestad.

Did you look for insect nests in the trumpets?

N4061 said:

Looking for a little trouble shooting help. We have dual electric horns by AFI that are nine years old. Both appear to have gone out. Pushing the button at the helm only yields a soft short sound. I checked out all wiring from the switch to the horns and everything appears tight. No corrosion anywhere. Pulled the backs off both horns and everything looks clean and tight. Any ideas? Thank you John T. N3522 La Tempestad.

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We have the same ones I think, are yours powered by a small compressor about the size of a soup tin? If so we have the same ones, when we first got the boat we tried them and they gave out this high pitch sound, so we immediately replaced them. Not sure if it's possible to fix. But it was easier for us to just by a whole new set and then we have a backup compressor.

Here's a link.
Dual Trumpet Marine Air Horns

Play around with the screws behind the back cover. It worked for me on my parent's boat many years ago. This was before the ubiquity of the internet, but I saw the screws and played with them, and voila it worked.

Here is the official version:

I have a dual trumpet electric horn that doesn’t want to sound. It just makes a clicking/chirping sound. What can I do?

Posted on June 21, 2012 by Shad Technical Service Representative

We suggest bench-testing the horn and wiring it directly to a 12 volt battery. If it works fine when doing this, then the problem is most likely within the application’s wiring. If the horn still only puts out a clicking sound, that is usually a symptom of one side trying to draw more amps than the other which causes them to cancel each other out. Remove the rear cover and find the screw in the center of the sounding mechanism with a small red dot on or next to it. Turn that screw a little bit counter clockwise and eventually the horn should start to sound properly. If not, keep trying each side, back and forth, counter-clockwise or clockwise. If still no positive reaction after all that, it’s time to replace the horn.

The compressors get gummed up after a while. Give it a good hosing down the air outlet with an electrical contact cleaner, the type that contains a lubricant is best. Sometimes a drop or two of oil down the same place will loosen it up. You don't use the horn often enough to wear out the motor - you will find its the pump that's the issue.

I have resurrected two horn sets like this, both of which were about 30 years old. The trumpets were fine, although sometimes there is corrosion on the diaphragm, but it doesn't seem to matter.

All this, of course, is if your horns are powered by a compressor.............

N4061 said:

We have dual electric horns by AFI

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N4712 said:

are yours powered by a small compressor

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Xsbank said:

if your horns are powered by a compressor.............

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Northern Spy said:

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We have the electric versions on our Camano ( funny isn't it?) they gave a soft sound as described above. We replaced them. Just replace them, after all you own a Nordy.
Sears.com

No compressor. It's a vibrating diaphram type and has an adjustable electrical contact screw. When you push the button power is applied to an electromagnet which pulls the diaphram which then pulls open the electrical contact which breaks the circuit so the diaphram relaxes and remakes the contact and starts the cycle all over again.

At 9 years old they may not be worth it. They ARE NOT ALL S.S.

I have them and every year untill this last, one of the pair would need a tweak. Last summer no way, the horn wouldn't work so they will be gone this year.

I will try Ongaro horns but won't get my hopes up too much.

I solved a similar problem on my old Sea Ray with a portable jump start battery pack. When bypassing the switch and wiring, the horns worked perfectly. Bypassing the switch but still using the ship's wiring sounded the horns. It turns out the problem was in the switch. Replacing the switch solved the problem.

It turns out the problem was in the switch. Replacing the switch solved the problem.

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This is very common as cheap switches will only have an AC rating , and a far better switch is required to turn off DC.

Assuming they are "electric" horns, first determine that the problem is not with the boat's wiring or switches. Check to make sure there's only a slight voltage drop at the horns.

Try adjusting the screws as in post #4. If that doesn't work, take them apart (on a bench, you'll have a very hard time doing this installed on a boat without losing any parts). Take notes or photos so you can put everything back together exactly as you took it apart.

You will find a set of electrical contacts. Soak a piece of thin cardboard with electrical contact cleaner, pry the points apart, insert the cardboard an pull it back and forth to clean the contacts. If they are in really bad shape you may have to burnish them with very fine emery cloth (and spray with the cleaner afterward). Put everything back together and try them. You will almost certainly have to adjust the screws to get the loudest sound.

Put the covers on and reinstall. If you decide to replace them, Ongaro is probably better than AFI and you can search the web for a good price.

We had the same problem with the same model electric horn and "solved" it much as described previously. BUT, bottom line is that these horns are useless even when they work! After a near run-in with a larger steel vessel during thick fog we installed a pair of Buel air horns with an automatic fog sounder. Would suggest you consider doing he same, especially if you are in a fog area. Now, we sound like the Queen Mary -- or we still have our quiet "inside" voice with the electric horns.

Chrisjs said:

We had the same problem with the same model electric horn and "solved" it much as described previously. BUT, bottom line is that these horns are useless even when they work! After a near run-in with a larger steel vessel during thick fog we installed a pair of Buel air horns with an automatic fog sounder. Would suggest you consider doing he same, especially if you are in a fog area. Now, we sound like the Queen Mary -- or we still have our quiet "inside" voice with the electric horns.

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As I want Chuck Norris to cower in fear when I hit the horn, I think the above is the perfect solution !

Those air horns would be nice but you would easily top $1K to install one. The large Ongaro dual trumpet horns are plenty loud. You pay your money and take your choice.

Original equipment boat horns on most boats are pretty much ineffective toys.

The cheap solution and a good backup is one of the portable plastic horns with the replaceable canister for about $15. Plenty loud and you can point it where you want the sound to go.

Reality for me and most cruisers I know, the fog horns are relegated to the electric trumpet hooked to a hailer or capable radio and automatically blown...these are usually not cabable of being heard by many small boaters.

It's because we are inside with just enough engine noise and don't open the door or stick our head out enough to hear one or the yahoo's in their outboards are screaming along and can't even hear the guy next to him shouting "look out for that trawler we are about to ram at 30 knots!"

For those of you with both air horns and automatic signal controllers......but I think you are the rarity rather than the rule unfortunately.

I was actually able to get the Buells used on Ebay for short money - I think they came off of an ambulance!! Very manly sound!! The sail boat air horn thing is useful when you are specifically trying to get someone's attention but does not help with the fog situation. We had just run about 40 miles in very thick (barely see the bow) fog relying on VHF and radar. The electric horn with auto sounder was on. Even though we knew there was a vessel nearby it was hard to know exactly where and distance from our boat, until this 80ft steel fishing boat came down our starboard side. I swear nobody was in the wheelhouse! So, I added a decent (trilens) radar reflector and the air horns with automatic fog sounder (long blast every 2 minutes). At least it feels safer, plus like I said - very manly!! I now consider a decent air horn to be a necessity not a luxury.