Horn broken

[marmaduke]

The horn of my narrowboat has stopped working. When keeping the horn switch engaged, it seems to give off smoke like it's overheating. Any ideas what it could be? The connections all seem sound to me and I can't see anything particularly suspect. Though I've not dissected a boat horn before, so what do I know. Here's a pic of it. Any ideas?

 

[cheshire~rose]

Is it the switch that is giving off smoke or the horn?

[Guest]

Sounds like an internal short of some sort.

 

I wouldn't bother dissecting it TBH, they are very cheap to replace.

[marmaduke]

It's the horn that gives off smoke

[Kwacker]

Sounds like it would be more useful to an Apache.

[PaulG]

All electrical equipment contains smoke. It's essential for correct operation.

If you let the smoke out, then the equipment will not work any more.

Try getting some replacement smoke - it's a Lucas standard part:

[Alan de Enfield]

All electrical equipment contains smoke. It's essential for correct operation.

If you let the smoke out, then the equipment will not work any more.

Try getting some replacement smoke - it's a Lucas standard part:

 

Judging by the part number that was made about 20 years ago - they developed a new 10 digit numbering system in the mid 90's.

 

It probaby won't work as it will be beyond its best before date - but having said that - most of Lucas manufactured equipment was beyond it best before date prior to sale.

 

Lucas is an acronym for Loose Unsoldered Connections and Splices

 

• The Lucas motto: "Get home before dark."
• Lucas is the patent holder for the short circuit.
• Lucas - Inventor of the first intermittent wiper.
• Lucas - Inventor of the self-dimming headlamp.
• The three position Lucas switch - Dim, Flicker and Off.
• The Original Anti-Theft Device - Lucas Electrics.
• Lucas systems actually uses AC current; it just has a random frequency.
• "I have had a Lucas pacemaker for years and have never had any trou..."
• If Lucas made guns, wars would not start.
• A friend of mine told everybody he never had any electric problems with his Lucas equipment. Today he lives in the countryside, in a large manor with lots of friendly servants around him an an occasional ice cold shower...
• Back in the 70's, Lucas decided to diversify its product line and began manufacturing vacuum cleaners. It was the only product they offered which did not suck.
• Q: Why do the British drink warm beer? A: Because Lucas makes their refrigerators
• Alexander Graham Bell invented the Telephone.Thomas Edison invented the Light Bulb. Joseph Lucas invented the Short Circuit.
• Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars,kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."

[PaulD]

The horn of my narrowboat has stopped working. When keeping the horn switch engaged, it seems to give off smoke like it's overheating. Any ideas what it could be? The connections all seem sound to me and I can't see anything particularly suspect. Though I've not dissected a boat horn before, so what do I know. Here's a pic of it. Any ideas?

 

Is the wire to the coil touching the A shaped bracket that the cover is fastened to? Side view would show it better.

[John V]

just check that the contacts aren't welded together, if they are not then the coil almost certainly has a internal short (the technical term is F$$$$d)

[marmaduke]

It is probably 34 years old, so maybe it is worth getting a new one. Thanks all for the confirmation.

 

M

[PaulG]

I'd check that the positive terminal is not shorted to the mounting strap. It look pretty close.

[nicknorman]

just check that the contacts aren't welded together, if they are not then the coil almost certainly has a internal short (the technical term is F$$$$d)

I think the contacts being welded together is the most likely issue. The contacts are pulled open by the magnetic field to interrupt the current, the magnetic field collapses and the contact, current and magnetic field are thus reinstated, all repeated rapidly. That is how the horn toots! If the contacts are welded together the current is not interrupted and the coil is not designed to be continuously connected to the power, so will rapidly overheat.

[Sir Nibble]

I've fixed loads of these! If the picture was taken from the other side it would show the contacts. The bottom one is adjustable, being threaded with a locknut a bit like ye olde magneto contacts. Adjust it down until it opens then back until it just touches plus about 1 1/2 turns. That should get noise, then adjust by trial and error in small increments for best beep.

[luctor et emergo]

I've fixed loads of these! If the picture was taken from the other side it would show the contacts. The bottom one is adjustable, being threaded with a locknut a bit like ye olde magneto contacts. Adjust it down until it opens then back until it just touches plus about 1 1/2 turns. That should get noise, then adjust by trial and error in small increments for best beep.

^^ this.

 

Although the smoke may indicate another problem too.

All electrical equipment contains smoke. It's essential for correct operation.

If you let the smoke out, then the equipment will not work any more.

Try getting some replacement smoke - it's a Lucas standard part:

<p>

 

 

Judging by the part number that was made about 20 years ago - they developed a new 10 digit numbering system in the mid 90's.

 

It probaby won't work as it will be beyond its best before date - but having said that - most of Lucas manufactured equipment was beyond it best before date prior to sale.

 

Lucas is an acronym for Loose Unsoldered Connections and Splices

 

• The Lucas motto: "Get home before dark."
• Lucas is the patent holder for the short circuit.
• Lucas - Inventor of the first intermittent wiper.
• Lucas - Inventor of the self-dimming headlamp.
• The three position Lucas switch - Dim, Flicker and Off.
• The Original Anti-Theft Device - Lucas Electrics.
• Lucas systems actually uses AC current; it just has a random frequency.
• "I have had a Lucas pacemaker for years and have never had any trou..."
• If Lucas made guns, wars would not start.
• A friend of mine told everybody he never had any electric problems with his Lucas equipment. Today he lives in the countryside, in a large manor with lots of friendly servants around him an an occasional ice cold shower...
• Back in the 70's, Lucas decided to diversify its product line and began manufacturing vacuum cleaners. It was the only product they offered which did not suck.
• Q: Why do the British drink warm beer? A: Because Lucas makes their refrigerators
• Alexander Graham Bell invented the Telephone.Thomas Edison invented the Light Bulb. Joseph Lucas invented the Short Circuit.
• Recommended procedure before taking on a repair of Lucas equipment: Check the position of the stars,kill a chicken and walk three times clockwise around your car chanting:" Oh mighty Prince of Darkness protect your unworthy servant.."

Edited August 12, 2014 by luctor et emergo

[NMEA]

It always worries me when I hear the word smoke without the words fuse blowing or breaker tripping, of course it is possible even with the correct rated over current protection but check the value matches any new horn you fit.

Edited August 13, 2014 by NMEA

[Pete & Helen]

A horn like a transformer can suffer from vibration over the years. The coil windings are normally dipped in varnish or or a hard wax to stop the vibration and the wires wearing against each other causing a short. If a short does happen then it will create a hot spot and the varnish or wax will heat up to the point of smoking first, then eventually fail altogether which could present its self in many a form, fire,fuse blowing or simply just stop working.

 

You could if you wanted to restore the horn for aesthetic reasons, get the winding redone, but looking at the picture I would just bin it and get a new one.

[RLWP]

One of my ancestors worked for Joseph Lucas himself in Little King Street

 

Richard

[magnetman]

I have old French train horn I got in a street market for 2 euros. Fire extinguisher I found in the cut (older water type with Schrader valve) emptied and charged to 80psi with a small 12v tyre compressor. Gas hose to join fire extinguisher to horn for high volume air transit. Pull fire extinguisher lever and you can see what happens

 

Its suitably loud and very simple with electric just used for charging up the air tank.

 

You do need to be able to accommodate a fairly large (like on trains) fire extinguisher though and have it accessible from the steering position...

[smileypete]

Agree with the others that the horn itself may need tweaking, but those crimp connections don't look great either.

 

Probably not unusual for a boat and often work OK, but if the cable run is long and the cable size is marginal, poor connections can be a make or break (or not quite make enough ).

 

There's a bit on crimping in this recent topic on wiring:

 

http://www.canalworld.net/forums/index.php?showtopic=68581#entry1363800

 

A decent crimp connection made with a ratchet crimper will look something like this:

 

 

If the sleeve on a crimp connection has slumped back towards it's original shape , it's a good tell-tale of a poor connection that's started to heat up.

 

This is most likely to happen where a cheap (non ratcheting) crimp tool has been used, and/or where plain stranded copper wire has been used in harsh conditions, and gets corroded:

 

 

So for best results a ratcheting crimper is the tool to use, along with wire with tinned strands for harsh conditions like moisture, excessive damp, salt water air.

 

cheers, Pete.

~smpt~

Edited August 13, 2014 by smileypete