Dave 2 Posted July 8, 2020 Report Share Posted July 8, 2020 Hi all my trumpet horn on my boat stopped working today I’ve done all the basic checks all okay, stripped down the horn inside it has a set of points which were closed together but there was power, should there be a gap and has anyone any idea how it works. Link to comment Share on other sites More sharing options...
Tracy D'arth Posted July 8, 2020 Report Share Posted July 8, 2020 The contacts should be closed. On applying power the electromagnet pulls the diaphragm and the contacts open, removing the power, it repeats ad infinitum, and makes a noise! There is usually an adjustment screw to set the opened gap and hence the noise. TD' Link to comment Share on other sites More sharing options...
Dave 2 Posted July 8, 2020 Author Report Share Posted July 8, 2020 Hi thanks for your response so do I adjust the contact screw till they are just touching? not sure what the problem is. Link to comment Share on other sites More sharing options...
Tracy D'arth Posted July 8, 2020 Report Share Posted July 8, 2020 2 minutes ago, Dave 2 said: Hi thanks for your response so do I adjust the contact screw till they are just touching? not sure what the problem is. Yes, provided you are sure that the failure is not due to low voltage caused by bad connections, bad horn button or low batteries. It is unlikely to have gone out of adjustment on its own. Try cleaning the points first. TD' Link to comment Share on other sites More sharing options...
Dave 2 Posted July 8, 2020 Author Report Share Posted July 8, 2020 Hi I’ve got over 12 volts at the horn contacts when the horn button is pressed it powers the points, I’ll have a go at cleaning the points. Thanks again for your help Link to comment Share on other sites More sharing options...
zenataomm Posted July 8, 2020 Report Share Posted July 8, 2020 Google is your friend .... https://www.google.co.uk/search?q=how+an+electric+horn+works&sxsrf=ALeKk03MjW0SeymX_D9tKMIWT3o2NKwadQ:1594242844668&source=lnms&tbm=isch&sa=X&ved=2ahUKEwjQrsSzyb7qAhVTtHEKHacbD2IQ_AUoAnoECAwQBA&biw=1600&bih=752 Link to comment Share on other sites More sharing options...
WotEver Posted July 9, 2020 Report Share Posted July 9, 2020 12 hours ago, Dave 2 said: Hi I’ve got over 12 volts at the horn contacts when the horn button is pressed it powers the points, I’ll have a go at cleaning the points. That’s a very confusing sentence. Are you measuring 12V at the horn, with the horn connected, when the horn button is pressed? If so, and if you have the horn disassembled, you should see movement in the diaphragm when the button is pressed. Link to comment Share on other sites More sharing options...
ditchcrawler Posted July 9, 2020 Report Share Posted July 9, 2020 1 hour ago, WotEver said: That’s a very confusing sentence. Are you measuring 12V at the horn, with the horn connected, when the horn button is pressed? If so, and if you have the horn disassembled, you should see movement in the diaphragm when the button is pressed. Unless the points are not making contact Link to comment Share on other sites More sharing options...
WotEver Posted July 9, 2020 Report Share Posted July 9, 2020 3 hours ago, ditchcrawler said: Unless the points are not making contact Indeed. Link to comment Share on other sites More sharing options...
Dave 2 Posted July 9, 2020 Author Report Share Posted July 9, 2020 Hi I’ve measured voltage at the points 13 volts and points are closed no movement, cleaned the points refitted still no joy, Might have to buy a new horn! Link to comment Share on other sites More sharing options...
WotEver Posted July 9, 2020 Report Share Posted July 9, 2020 6 hours ago, Dave 2 said: Hi I’ve measured voltage at the points 13 volts and points are closed no movement, cleaned the points refitted still no joy, You need a new horn sir. Link to comment Share on other sites More sharing options...
Dave 2 Posted July 10, 2020 Author Report Share Posted July 10, 2020 A new horn not made in China is now on order so it’s a big shout until it arrives. Link to comment Share on other sites More sharing options...
LadyG Posted July 3, 2022 Report Share Posted July 3, 2022 (edited) My horn was fitted three years ago, it stopped working a while ago, I messed about with the fuses, sort of push things, might be relays, I don't know the difference. Anyway, I've pushed the relay/fuse things again so they are all the same. Still no horn. The horn is mounted on a swivel. I've it pushed up and down, but still no effect. If I dismantle it should there be power, as the button is not depressed? Update, I can't get in to diaphragm, but the outer housing is full of water but terminals look fairly clean. Edited July 3, 2022 by LadyG Link to comment Share on other sites More sharing options...
Tony Brooks Posted July 3, 2022 Report Share Posted July 3, 2022 4 minutes ago, LadyG said: My horn was fitted three years ago, it stopped working a while ago, I messed about with the fuses, sort of push things, might be relays, I don't know the difference. Anyway, I've pushed the relay/fuse things again so they are all the same. Still no horn. The horn is mounted on a swivel. I've it pushed up and down, but still no effect. If I dismantle it should there be power, as the button is not depressed? I Not normally but on boats you never know, especially if there is a bow thruster battery and someone has decided to use that to blow the horn with a relay being energized by the push button. Does it blow with the engine running and revving? Horns are often wired with undersized cables for the run length. It may have its own fuse/circuit breaker. Try disconnecting the wires from the horn and insulating them. Joining the cables behind the push button and then seeing if you have battery voltage between the two wires at the horn end. Link to comment Share on other sites More sharing options...
Ray T Posted July 3, 2022 Report Share Posted July 3, 2022 (edited) Get one of these, has historical precedence. 😃 A shunters horn. B & W photo from Life Magazine, photograph by David Schermann. Edited July 3, 2022 by Ray T Link to comment Share on other sites More sharing options...
LadyG Posted July 3, 2022 Report Share Posted July 3, 2022 (edited) 2 hours ago, Tony Brooks said: Not normally but on boats you never know, especially if there is a bow thruster battery and someone has decided to use that to blow the horn with a relay being energized by the push button. Does it blow with the engine running and revving? Horns acre often wired with undersized cables for the run length. C It may have its own fuse/circuit breaker. Try disconnecting the wires from the horn and insulating them. Joining the cables behind the push button and then seeing if you have battery voltage between the two wires at the horn end. Aha, no I can't get to horn push button without chaos. The bow thruster buttons are pretty close to the horn button and of the same design. The wires at the horn end look pretty new, not sure if I can unscrew them at the front end, then what should I do? Horn s not working at all, I discovered the outer housing full of water, and some signs of corrosion, but not excessive! I need to get in to the actual diaphragm bit, but it is sealed with a gasket, I ve removed a little grub screw thing and left it in the sun. PS it's not the standard trumpet, it's Italian, short think, s/s or chrome and chromed plastic. PS the electrics have been doing odd things today, needles to say after I turned everything off and on and reset everything I could thin of, the engine alarm went off as I was cruising, I turned it off a d one a few times and it s normal. Noticed that the car radio not working again. A frequent fault, but after starting the engine and flicking the toggle switch it started up again. Not much use of course as speakers are at the other end and it intermittently works Edited July 3, 2022 by LadyG Link to comment Share on other sites More sharing options...
Alan de Enfield Posted July 3, 2022 Report Share Posted July 3, 2022 56 minutes ago, LadyG said: Aha, no I can't get to horn push button without chaos. The bow thruster buttons are pretty close to the horn button and of the same design. The wires at the horn end look pretty new, not sure if I can unscrew them at the front end, then what should I do? Horn s not working at all, I discovered the outer housing full of water, and some signs of corrosion, but not excessive! I need to get in to the actual diaphragm bit, but it is sealed with a gasket, I ve removed a little grub screw thing and left it in the sun. PS it's not the standard trumpet, it's Italian, short think, s/s or chrome and chromed plastic. PS the electrics have been doing odd things today, needles to say after I turned everything off and on and reset everything I could thin of, the engine alarm went off as I was cruising, I turned it off a d one a few times and it s normal. Noticed that the car radio not working again. A frequent fault, but after starting the engine and flicking the toggle switch it started up again. Not much use of course as speakers are at the other end and it intermittently works Had you considered getting an electrician to have alook at your wiring system - you do seem to have regular and on-going problems. Link to comment Share on other sites More sharing options...
Tony Brooks Posted July 3, 2022 Report Share Posted July 3, 2022 1 hour ago, LadyG said: Aha, no I can't get to horn push button without chaos. The bow thruster buttons are pretty close to the horn button and of the same design. The wires at the horn end look pretty new, not sure if I can unscrew them at the front end, then what should I do? Horn s not working at all, The wires must have been connected somehow, even if they are flyleads permanently fixed inside the horn and then routed to connectors where they join the boat's wiring. You need to establish if you have current at the horn so if you can't get at the horn terminals push a pin or needle through the cable insulation and connect the meter to that. Then press-gang a passing boater or walker to press the horn button. I think those horns are toys for boys rather than a decent bit of kit and they are often riveted together. If it had water in it I suspect you need a new horn. Link to comment Share on other sites More sharing options...
George and Dragon Posted July 7, 2022 Report Share Posted July 7, 2022 On 03/07/2022 at 14:43, LadyG said: My horn was fitted three years ago, it stopped working a while ago, I messed about with the fuses, sort of push things, might be relays, I don't know the difference. Anyway, I've pushed the relay/fuse things again so they are all the same. Still no horn. The horn is mounted on a swivel. I've it pushed up and down, but still no effect. If I dismantle it should there be power, as the button is not depressed? Update, I can't get in to diaphragm, but the outer housing is full of water but terminals look fairly clean. Take it down, make a way to connect it across your starter battery (two leads). If it works the problem is in the circuit, otherwise you need a new horn. A motor factor will have something that works or you can spend more to get something pretty. Link to comment Share on other sites More sharing options...
Featured Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now