dual elect. horns 1987 32 aft cabin

[drmax]

Going through some other items on friends boat and horns just make a thump sound when pressing button. I have not torn into them yet, but what typically is the issue's with these? I'll assume the diaphragm's are messed up. But seems odd to the fact they both are doing the same. Hand on the rear of horns and can feel they are both thumping. Could even be full of bug nests for all I know. I'll do a quick check for 12 volts making to the units, then next I'll looks down the tubes for mud dobber nests. Anyways...if someone else has had similar issues, I'm listening. Thx for any others advice...DM

[km1125]

Could be poor connections at any point. If you measure voltage, then make sure there's a load on the end, preferrably leaving the horns hooked up when you do it. The switch contact might be just slightly corroded and so could any of the push-on crimp connectors.

The contacts in the horns will get corroded if you DON'T use them enough. For this issue, you can take another 12V battery and run it in SERIES with the boat so you're feeding the horn with 24v temporarily. Blast the horn a few times, then put it back on the 12V boat feed and try it.

I have a couple little squares of soundown foam acoustic insulation. I bungie them over the horn ends and blast the horn a couple times if I haven't used them in a while. Whenever I'm out on the water and there's no boats around, I'll sound the horn a few times, or let the kids do it to also entertain them. Exercising them works just like your muscles.

[Viper]

Can be electrical issue, debris in the throat, or a dirty or torn diaphragm in the horn.

[bud37]

Just curious here, I seem to remember there were adjustment screws on some that when turned would alter the tone and by working the screw back and forth it would free them up to work again.

[km1125]

On many of them there are adjustment screws. You have to take the back cover off, which is held on with one screw in the center (possibly under a sticker). Once, I tried to do this but after taking the screw out I could not get the cover off. Hours later, I heard a "ding, ding ding, SPLASH" and the cover had popped off and fell into the drink. About 4 years later, I had a diver friend go into the slip to find a canvas that had blown off the boat, and he also found the cover.

The higher the tension on the screw, the higher the pitch but it also required more current to overcome the spring. You can back the screw out, use the horn a few times, then re-adjust the screw for the right tone. I find it easier to try the 24V method first, which works pretty good.

[Cooler]

Had a similar issue. Horns sounded like a wounded duck, and low volume. Pipe cleaner removed some spider web, sprayed a little cleaner straight up the horn, and BINGO! They sound loud and 2 tone pitch, just like new. er