Air horn troubleshooting, MC9

[plyonsMC9]

Good morning group!

I have a problem with an intermittent air horn.  By this I mean, when I hit either the floor switch or the buttons on the steering wheel, the air horn may or may not activate.  And if it does, it may not stay activated while the floor or steering wheel buttons are depressed.  More specifically, I may have to strike the buttons multiple times to get any kind of extended horn blast.  Well, actually, more of a VW "honk" but that is another story.

How would I start to troubleshoot this?  Is there a quick list of likely suspects as to what causes this problem? 

Thank you!  Best Regards, Phil

[gumpy]

Air horns?  My MC9 has electric horn by the steering box.  I also have intermittent problems, but mine are caused by the buttons on the steering wheel. They don't have very good contacts in them, so you have to get them pushed "just right" to get them to work. The floor switch works well.

If you have similar setup, with electric horns, and not really air horns, then see if you can isolate it to the buttons or not. If you wiggle the button a certain way and make it work, then the problem is the contacts in the buttongs. If not, start by checking connections on the horns themselves. They will likely be corroded. Next, find the horn relay in front junction box. Check connections there. Short relay to make sure it works properly.

There isn't much in the system that can go wrong.

If you really do have air horns, then disregard this post, as it probably doesn't apply.

[plyonsMC9]

Well, that would be embarrassing.  OK, I will look @ the horn some more.  First determining whether it's electric or air.  Sigh...   I thought there was an air hose going to the horn, but of course, I could be totally wrong - again.  If in doubt, I will post a pic.

Thanks Craig,  Phil

[FloridaCliff]

Phil,

My GMC had a floor air horn and a steering wheel electric horn.

I ended up putting in an electric valve for my air horn and eliminated the stock electric horns.

I used the steering wheel button for the activation switch for the air solenoid.

My electric horn was intermittent at best.

When I took the steering wheel off to fix my turn signals, I cleaned the contacts on the steering wheel button and it works the air horns perfect.

Cliff

[belfert]

Air horns are usually pretty long while electric horns are short. 

I try to NEVER use my horn, but my friend found that the button on the floor next to my dimmer switch is an air horn and the steering wheel button is an electric horn.  About the only time I have ever used a horn is in a parking lot when I'm right behind a dummy who is backing right into me.

Off the topic, but a lot of people use horns way too much.  They are supposed to be emergency devices, not a way to express your displeasure at someone else's driving.

Brian Elfert

[gumpy]

Off the topic, but a lot of people use horns way too much.  They are supposed to be emergency devices, not a way to express your displeasure at someone else's driving.

Yeah, that's what the middle finger is for!  Of course, it never hurts to accentuate the middle finger with a blast from a train horn 

[Ednj]

Phil,
That sounds like an electric horn ( check the ground).
My "air horn" only works when the coach is totally aired up.

[plyonsMC9]

Do your air horns sound different than the electric horns?  Just curious - whether I use either the steering wheel or floor button, the horn still sounds like a weanie horn.  No difference.

Inquiring minds want to know!   

Best Regards, Phil

[Ednj]

Phil,
There is a little difference.
The steering wheel and foot switch sound like a europen car, but the air horn is the loudest horn I've ever heard.

[plyonsMC9]

     Those are WAAAAYYYY TOOO COOOOOL       

Nice work Ed!

- Phil

[JackConrad]

The say you can tell a redneck by the number of horns on his vehicle sooooo! I have 1 pair of electric horns, 2 pair of air horns and 1 train whistle. Here is how they are connected. On the switch panel on the left side of the drivers seat in our MC-8 is an electric switch for the electric horns, a ball valve for the train whistle and a double throw electric switch for the 2 pair of air horns (down is the low tone pair and up is for the higher tone pair). The horn buttons in the steering wheel are my Panic Buttons When I hit either of these, the electric horns and both pair of air horns are activated. I have never used this mode yet, except to test the operation. This mode is "for emerency use only".  Jack

[gumpy]

The horn buttons in the steering wheel are my Panic Buttons When I hit either of these, the electric horns and both pair of air horns are activated. I have never used this mode yet, except to test the operation. This mode is "for emerency use only".  Jack

... and in the news today, an automobile vanished on the freeway and investigators are trying to determine why. Witnesses say a large motorhome with what's described as a lightning bolt on the side of it was traveling along at a safe speed when the driver of a small automobile cut in front of the motorhome and slammed on his brakes. The witness said there was a, "cacophony" of sound which seemed to emenate from all parts of the motorhome, and in an instant, the small automobile just disappeared in a cloud of smoke! The witness, a self-proclaimed redneck, said of the explosion, "It was like these here harmonics just all came together at once and the dang thang  just went... BOOM!"  Neither the motorhome, nor it's driver, could be located. Investigators suspect some sort of perpetual energy machine may be in use on the motorhome.

[plyonsMC9]

Craig, VERY well done, says Phil, LOL        

[buswarrior]

Hello Phil.

MCI was fond of putting an electric switch in place of the foot operated air valve when an air horn was not optioned for the bus.

If the foot switch looks suspciously similiar to the top of the high beam switch, it's electric. The air horn foot button has a rubber type bulb shaped cover.

If you had an air horn, you'd know it from standing on the foot control!

Both MCI and Prevost have gone to electric solenoids for air horn activation in the new stuff I drive part-time.

happy coaching!
buswarrior

[JackConrad]

... and in the news today, an automobile vanished on the freeway and investigators are trying to determine why. Witnesses say a large motorhome with what's described as a lightning bolt on the side of it was traveling along at a safe speed when the driver of a small automobile cut in front of the motorhome and slammed on his brakes. The witness said there was a, "cacophony" of sound which seemed to emenate from all parts of the motorhome, and in an instant, the small automobile just disappeared in a cloud of smoke! The witness, a self-proclaimed redneck, said of the explosion, "It was like these here harmonics just all came together at once and the dang thang  just went... BOOM!"  Neither the motorhome, nor it's driver, could be located. Investigators suspect some sort of perpetual energy machine may be in use on the motorhome.

Craig,   I like that!!.  I printed it out to put in our Orange Blossom Special II scrapbook.  Jack