Air horn woes

[tbar123]

So far on my 84' m923 I have replaced the solenoid(used) 3 times, replaced the actual horns,replaced all the grounds,the horn switch(bottom of steering column),the steering column,horn button,and have checked for air pressure,and proper voltage. Everything checks out except the horns. They blew air but no noise so I switched back to the originals, and now I'm going to put a new air horn solenoid in and if that doesn't fix it, Then I'm going to put a push button in and call it done.But I really like to keep with original equipment but what I have into the horn I have to call it quits after this. Any info on what might also might be the cause would be greatly appreciated. Thanks in advance!

 

[ranchhopper]

Get yourself a set of these they work great and will last a life time I just polished them and painted them up for my parade truck I had a set just like painted flat black I put on my 923.

 

[Cape Coastie]

Where can I get a set like that cheap? Originals have a pretty weak high pitch sound.

 

[ranchhopper]

There isn't any of them for cheap I bought the last two I have at a great price $850 each as close to new as it gets they get $1500 for them on various auction sites and they were pretty well used they are pretty big the horn pictured weighs around 30 pounds.

 

[JohnnyBM931A2]

Where can I get a set like that cheap? Originals have a pretty weak high pitch sound.

For what it's worth, someone told me that there is a screw or something on them to adjust the sound. Never actually took a look at that though. I do agree that the stock horns leave a lot to be desired.. I say you should get yourself a train horn

 

[ranchhopper]

Same model K5LLA horn on top of my bobbed deuce in my avatar.

 

[JohnnyBM931A2]

Same model K5LLA horn on top of my bobbed deuce in my avatar.

Do you have any sound clips?

BTW, always nice to see another member in Northern Illinois

 

[ranchhopper]

No sound clips but lots of them on u-tube for the Nathan airchime K5LLA.

 

[Cape Coastie]

I knew they weren't cheap. I added a set of boat air horn trumpets to the existing set and it sounds much better. There are tone adjustment screws on the back side but they like to corrode in their holes and break off when you try to adjust them. If you try use a lot of penetrating spray, PB Blaster works great.

 

[74M35A2]

There is a diode on the ground side to dampen the inductive spike when the solenoid releases. This is wrapped in tape or shrink tube where the horn wire is grounded by the horn bracket. For my case, this diode was roasted and my horn stuck on. Not sure if this is the case for you.

 

[steelandcanvas]

Proper troubleshooting procedures out of the TM may have kept you from throwing parts at your problem. Here is a wiring diagram to start with: TM 9-2320-209-20-2-2. I realize the referenced TM is for a Deuce, but it shouldn't be much different from a 5 ton.

 

[BEASTMASTER]

there is an allen screw on the back of each horn. first stuff a rag in one horn, I mean use a screwdriver and jam it in there. build up air pressure and have someone sit in the truck and keep pressing the button while u turn the allen screw to the pitch u want. then reverse the process for the other trumpet. I've got mine to sound like a fire truck. it sounds great in the parades. good luck . instead of running the truck to build air hook you're compressor to the air tanks.

you are adjusting the horn without the rag in it. then repeat on other horn.

 

[tbar123]

I actually did follow all the TM's to the letter. I found the problem ( by testing) ,put back together and no joy! Time and time again, So that's why I'm just going to keep throwing cash at it!

 

[dmetalmiki]

The horns are a nightmare. When they do go wrong, they usually stay wrong. My guess is it's nothing to do with all the parts you have replaced..it's simply the horns themselves are done. Just get yourself a nice truck train or boat horn, Less hassle and cheaper in the long run. ( every one of my trucks has an additional "wolo" fire chief horn fitted.) Awesome!. And The truck does get "noticed".

 

[tbar123]

I've even replaced the horns!

 

[Floridianson]

Did you check or maybe use another ground to the steering column. There was a ground strap from firewall to steering column on my trucks. If you go under the hood and unplug the horn trip wire from the column box and ground it out there does the horn blow?

 

[tbar123]

Yes sir, I replaced the box at the bottom of the steering column, the ground, and the column itself!

 

[TMNT]

Air horn woes!

Tbar, break it down to its components for testing. First, check for voltage at the solenoid when you press the horn button. If voltage checks ok, hook it up to the solenoid (no horn) and then press the horn button. Did a lot of air come out? Solenoid ok. Did a little bit of air come out? Check the solenoid for corrosion or obstruction. Check the air line for a kink or crimp. You could be getting air pressure but a restricted amount of air flow. Horns take a lot of pressure and flow.

Finally, check the horns. Use a compressor and air hose with a rubber-tipped blow gun. Press the rubber tapered blow gun tip into the hole where the solenoid goes. Pull the trigger. Did it scare the crap out of you, causing you to drop the horn and grab your ears? Horn is ok.

If the horn sounds weak, muffled or is way out of tune, take it apart and clean it up. The diaphragm can get rusty or really dirty, and it won't vibrate properly. Clean it all up with WD-40 and steel wool and then put it back together. Adjust the tone using the screws on the back, your shop air compressor, ear protection, and pray for patient neighbors. Or, stuff a rag in it like someone else said.

It sounds like you've replaced the major components at least once. I'd be suspicious of the air line/air flow to the horns.

 

[tbar123]

TMNT, I did all the electrical tests and everything checks out.I will try to hook up my compressor and check the original horns. Which brings me to my next question. Can the horns that don't have the screws on the back be adjusted?

 

[TMNT]

I'm not sure about that. I've only worked on deuce horns and several commercial truck horns. I would think there must be an adjustment of some type to tune them, but I've not worked on horns from a 900 series truck.