Electric Horn - horns work seprate but not together

[Soul Mate II]

I have a dual horn. It wasn't working and after reading on this site did a few tests. They old owners used speaker wire that got corroded. Replaced and got both horns to work INDIVIDUALLY but they won't work together. They work fantastic alone. The sound they make when together sounds like a clunk clunk.

Each horn has two wires that come off of them. One striped wire, One solid - I put the two striped wires together and two solids together and connected them to the power wire and got the clunk clunk. I have no problem replacing the horn but I would rather fix if possible.

Thanks for any ideas!!

 

[blaster]

What kind of switch is it? You say they work individually, are they on separate switches or wired together on one switch? Did they both work together before? What kind of horn are we talking?

 

[Soul Mate II]

Thanks for responding!

The switch is a rocker switch at the helm. I wired up the horns individually first to see if they both worked. Went to the switch tried the first it worked, rewired it for the second switch went to the switch and it worked. Went and wired both together to the power and they didn't work. Got a clunk clunk sound. I don't have a wiring diagram for the horns as they were existing. They are FIAMM Airtone A23 horns.

Maybe I should have a different wiring configuration? Maybe the wire is too small to carry the current that is required?

I appreciate any help you can provide

Happy New Year!

 

[h_gerry]

Could be you are not getting sufficient voltage to the horns. Check it with a meter to see what you have. If that is not it, the only other possibility is that you have reversed polarity to one of the horns.

 

[dpmulvey]

Stripe = negative.
Solid = positive.

What gauge wire are you using? Marine gauge is actually thicker than household.

Did you rewire all the way to the switch? If not, you may have a weak point "leaking" electricity. If so, im thinking the wire is not heavy enough to to carry the load required for both horns.

 

[JVM225]

Sounds like it may be a low voltage problem. Do they both work at cruising rpm when the alternator is putting out?

 

[dvx216]

Hook up both horns put a voltage meter on connection and take voltage reading when you push the horn button and see what your voltage is doing.

 

[Soul Mate II]

I removed and replaced only a section of the wire, the previous owner or someone used speaker wire that was really corroded.

It looks like the rest of the wire is 16 gauge. I didn't take it back to the switch...if I knew that was the problem, I would do it immediately...what gauge wire should I use?

The wire is spliced in 2 spots, maybe I have leakage there?

What gauge wire should I use? I will break out a volt meter and see what I have.

The boat is out of the water so I don't know what it will be like with the alternator on - the boat is plugged in.

Thanks all,

Steve

 

[dpmulvey]

Bingo!!!

16 gauge is too light. DAMHIK!!! Each splice is a potential point of failure.

Fish everything out. Now.... You can do this two ways.......right or cheap.......both will work....one will work a bit longer.

Wrong..... Get a 10/2 or 10/3 extension cord from HD and cut it to the proper length. Wire directly to the battery pass through the switch.

Right...... See above but use tinned marine 10/2 Romex.

Really right..... Fiamm uses a relay in their auto setups. If you seal it, you will be set for the foreseeable future.

OK. Three ways.

My 2 cents.

 

[War Eagle]

I have similar horns on my boat - and they are sensitive to low voltage. You can check the voltage across the horns at the closest connection (both sides) with a volt meter or test lamp. If the voltage drops from 12.6 by 1.5 volts or a 12 vdc test lamp dims noticeably when you try to blow them .... more than likely you have a corroded joint somewhere in either the ground side or positive side. You can find the corroded or high resistance joint by checking the voltage back thru the loop. Since the voltage drop across a resistance is proportional to the current thru it - one horn might work but the added current requirements of the second will double the voltage drop - and neither will work.

Another option is to just run a couple new wires (14 ga - min) temporarily from the ground (or negative) side and the +12 vdc buss to the horns and see if they blow.

Could also be corrosion in the switch or breaker. The breakers are notorious for corroding and instead of closing completely - just create a high resistance (semi closed) circuit. The result is low voltage at the load and a hot connection in the breaker. At 12 Volts - any significant resistance in the feed will drop the voltage available at the load - these horns are more sensitive to low voltage than most 12 vdc devices (lights, fans and such might dim or slow - but the horns just stop working or just go "clunk")

Best bet in the long run is to replace both wires all the way back to the ground bus and to the switch - 14 ga (min) "primary wire - stranded copper" at any auto parts or marine supply. Use marine grade, sealed butt splices if necessary - don't remember how the wires are made up at the horns.

And watch out for those "leaking joints" - I hate it when that happens - spills electrons all over the deck -- makes such a mess!

 

[dvx216]

16 awg is good for roughly 12 amps but you do not blow a horn for long periods of time and I don't think your horns would draw that many amps

 

[War Eagle]

The horns are basically mechanical ... and use a solenoid (electromagnet) with a set of interrupter contacts to generate all those db's. It takes a surprising amount of current to start them vibrating. If the voltage buckles (drops) due to high resistance in the supply - the armature may not move far enough to open the interrupter - and it just goes "clunk".

The average current is low ... but the cyclical starting current can be high enough to create problems - hence the need for a fairly large conductor.

10 ga is probably overkill, but when you are working with only 12.6 vdc -- every little bit of conductor helps!

And when you need the horn to get the attention of the beer barge .... one that sounds like a wounded moose is embarrassing as ... well!