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Topic: Air Horn Troubleshooting (Read 3126 times) previous topic - next topic

Air Horn Troubleshooting

I checked out the old posts regarding this issue, but could not reply because they were over 90 days old. In the past, my horns would start working after several attempts, usually on the way to the inspection station. On this trip, nothing. Using info in the past posts, I have checked the voltage on the solenoid when pushing the horn button and that part checks out. One reply said to apply 12 volts to the horn wire which is confusing as there is no horn wire (load wire) only the air line. So my question is, is there a further check for the solenoid? Also when changing the solenoid does the air system have to be completely drained, if the gauge ( where the solenoid is located) is showing no pressure? I can access the horn's air line through my overhead cabinet, so could I apply air to the horns to check them?
Thanks for any help you can provide. Also would a parts store have this solenoid?
Jerry
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional

Re: Air Horn Troubleshooting

Reply #1 –
Quote from: Jerryetc –
I checked out the old posts regarding this issue, but could not reply because they were over 90 days old. In the past, my horns would start working after several attempts, usually on the way to the inspection station. On this trip, nothing. Using info in the past posts, I have checked the voltage on the solenoid when pushing the horn button and that part checks out. One reply said to apply 12 volts to the horn wire which is confusing as there is no horn wire (load wire) only the air line. So my question is, is there a further check for the solenoid? Also when changing the solenoid does the air system have to be completely drained, if the gauge ( where the solenoid is located) is showing no pressure? I can access the horn's air line through my overhead cabinet, so could I apply air to the horns to check them?
Thanks for any help you can provide. Also would a parts store have this solenoid?
Jerry
                                    Jerry I would assume that the 12 volts to the horn wire you refer to is the hot side of the solenoid.The solenoid should open and close to allow air to the Hadleys if operating correctly. There should be two wires to the solenoid of course. I would absolutly dump all the air before disconnecting any airline. Also, I would think that you could get a replacement solenoid at a larger NAPA store or any truck parts store.
   
                              Dean
Dean & Deirdre

2012 Arctic Fox 22GQ
Was 2003 U270

Re: Air Horn Troubleshooting

Reply #2 –
If other things check out, you might check for mud daubers in the air horns. Happened to me on both a boat and my motorhome. Easy to disassemble and clear.

Re: Air Horn Troubleshooting

Reply #3 –
Thanks Dean and Bob,
I checked the voltage to the solenoid with the wire line side attached which should be the same as applying 12 volts to the solenoid. The other wire is a ground. I checked the horns for mud daupers first, as they have caused me problems with my heaters and my generator.  I am going to try putting air on the horns from my cabinets. If they blow, the solenoid is probably the problem.
Jerry
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional

Re: Air Horn Troubleshooting

Reply #4 –
You don't have to go into the cabinet to put air to horn. It would be better to connect both in & out air together at solenoid position and see if air lines & both horns work. You could use a shutoff valve between in & out air lines. This way you are testing everything around solenoid.

Re: Air Horn Troubleshooting

Reply #5 –
That would work Barry, but the way the solenoid is connected to the back of the air gauge makes it difficult to do. Much more room in the cabinet.
Jerry
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional

Re: Air Horn Troubleshooting

Reply #6 –
Today I disconnected the air line to the air horns from the solenoid and put air to it. Nothing. Took the lines loose from each horn and put air directly to each horn. Nothing. Took the horns off the coach and put air directly to each one. Still nothing. NAPA gets $47 for a new solenoid but I hate to buy something w/o knowing that it will fix the problem. Shouldn't the horns blow from applying air directly to them? Or does the solenoid increase the pressure? The horns are clear of bugs and nests. With the air line off the solenoid, shouldn't the solenoid open when horn button is pushed? Tomorrow I am going apply 12 volts directly to the solenoid and see if it opens. Any other suggestions out there?
Thanks,
Jerry
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional

Re: Air Horn Troubleshooting

Reply #7 –
Solenoid does not increase pressure, it just opens & closes air supply to horn. Air pressure should blow horn, if enough psi and no leaks in the lines. To test if things work without solenoid, connect solenoid's in & out lines together & start engine and if all is well horns should blow sometime before maximum air pressure turns off compressor.

To test solenoid, leave solenoid's input air line from compressor attached, remove solenoid's air line to horns , start engine, only when you put 12 volts positive and GOOD ground to solenoid wires, air should come out of solenoid.

Re: Air Horn Troubleshooting

Reply #8 –
I had one horn quit working. I put a rag in the working horn to muffle the noise. I then put a lot of air through the "broken" horn. I did not disconnect any lines, but simply used the horn button on the steering wheel. I tapped the back end of the offending horn a few times with a rubber mallet. It finally started working. I kept the air pressure above 90 psi while loosening up the reluctant horn.

I try to exercise the coach at least once a month. Exercise includes driving about 20 miles, including about 10 miles of highway speeds, honking the horns, moving the mirrors, running the generator, running all air conditioners and heaters, operating switches, etc. I've had no more problems with the horns since I started exercising them regularly.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Air Horn Troubleshooting

Reply #9 –
Hi guys,

James Triana once told me when the air horns don't sound right the back can be removed to clean the reed. Sometimes junk gets stuck there.
Jim Frerichs
2002 U320 42'

Re: Air Horn Troubleshooting

Reply #10 –
Thanks everyone!!
Barry, is there a psi level that has to be reached before the horns will blow? If so, I might not be putting enough pressure to the horns. I am using the air line off the compressor with an air blow gun attachment. I didn't try your earlier suggestion of tieing the two lines together because the soleniod is directly connected to the back of the pressure gauge. I did not want to remove the solenoid until I was sure that it was bad. I will try jumping out the solenoid as you suggested.
Thanks again.
Jerry
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional

Re: Air Horn Troubleshooting

Reply #11 –
Here is the link to Hadley's web site on how to trouble shoot their air horns.

Technical Docs - Hadley

Keith
Keith, Joyce & Smokey the Australian Cattle Dog
1995 U320 SE Extreme 40' WTBI Build # 4780, with a Honda CR-V hopefully still following behind.
Motorcade # 17030
FMCA # F422159

Re: Air Horn Troubleshooting

Reply #12 –
Jerry, Don't know at what psi horns will blow.

Re: Air Horn Troubleshooting

Reply #13 –
Thanks Keith and Barry.
'91 U240 GV / 36'
CAT 3208 w/Allison MT 643  4 speed
'10 Ford Flex

Growing old is mandatory
Growing up is optional