Brendan The Spit Posted July 8, 2011 Share Posted July 8, 2011 Title says it all really. I changed the steering wheel, all good, but I cannot figure out how the horn works.There's the sort-of-cigarette sized bit in the centre of the wheel coliumn that contacts the strip on the column at one end, and the sticky-outy bit of metal at the back of the horn at the other. I get that. There's also a bit of metal sticking out of the *side* of the horn. If that doesn't touch the boss, the horn doesn't sound at all. When I have that *resting* against the metal boss, the horn works, ie I push it, it honks. So this makes me think "Ah, it's a circuit, and pressing the horn completes that circuit so all is good."But no. When I push it *into* the boss, that is, so that the horn 'looks right' and is nicely seated, the horn sounds continuously, babes cry, gardener wake up from vegetable patch, ect ectSo what's going on there? Am I wrong about the circuit? Does any of this make sense? Would photos help? Do Fotherington-Thomas hav a face like a squished tomato? Ect. Link to comment Share on other sites More sharing options...
Deleted User Posted July 8, 2011 Share Posted July 8, 2011 Horns on Spits are temperamental; I have a button on the dash, no problems. Link to comment Share on other sites More sharing options...
BrendanD Posted July 8, 2011 Share Posted July 8, 2011 Lets try a helpful post rather than suggesting you butcher your dash......yes it does create a circuit, the pencil thing taking the current down to the metal strip and the circuit completing via the metal tube of the steering wheel.I think what's happening when you push it home is that the pencil thing is pressing on the horn button and making it switch 'on'.First, is the pencil thing the correct plastic and brass thing with a spring inside to take up the strain, or has it been bodged with a solid strip? they break and people bodge them.If its correct, is there any scope for adjusting the boss position to make some more space?RegardsBrendan Link to comment Share on other sites More sharing options...
heraldcoupe Posted July 8, 2011 Share Posted July 8, 2011 Manufacturers of aftermarket steering wheels rarely give much consideration to our horn push arrangements. I've seen numerous problems caused by them, there's no one-size-fits-all fix.Going from first principles, the contact ring at the top of the column is live, ie the return from the horn, the column itself is ground. So when the contact ring makes a circuit with the column, the horn sounds. The horn push button has a contact at the outside edge which connects to the steering wheel boss. The other contact is a tab which meets the end of the "horn pencil", a spring loaded plunger which has an insulated plastic outer casing. The other end of the horn pencil meets the (live) contact ring. When the horn push is pressed, it closes the circuit between column and contact ring - the contact is made within the push button, none of the other potentially moving parts should make or break contact.Here are a few suggestions where aftermarket wheels cause contact where it's not desired:1 - Steering wheel boss touches against contact ring at top of column.2 - Horn push "live" tab touches against steering wheel boss.3 - Horn pencil is a loose fit in the steering column, allowing it to skew and bridge between the tab and stering wheel boss.4 - Horn pencil too long causing similar fault to 3.From what you describe, I reckon 2 is most likely, when the horn push assembly is fully located the tab is contacting the boss.Cheers,Bill. Link to comment Share on other sites More sharing options...
PJM Posted July 8, 2011 Share Posted July 8, 2011 I had to shorten my pencil thing when fitting my Mountney steering wheel. Bit of trial and error to get it right and a new pencil thing required but cheap as chips so no harm done. I also permanently connected the metal tag on the inside of the horn push with an extra lead soldered to one end of the pencil thing and slid under the metal tag to get a good contact. By the way the pencil thing is called a brush and it comes in at least 2 sizes. Link to comment Share on other sites More sharing options...
Brendan The Spit Posted July 9, 2011 Author Share Posted July 9, 2011 Right, right, it's a brush, I knew that. Honest...The brush is indeed the original ie two ends of metal with a spring in between, in an insulated sleeve.OK, so I think it could be 1 or 2 above too because Rarebits describes exactly the way I think this all works. I'm about to nip out to the garage for another try. But just to clarify:* The brush should always be in contact with the contact ring, right?* The brush should always be in contact with the horn, right? This is because the horn, when pushed, doesn't actually cause anything to break or make contact externally, it's all within the horn mechanism. This is why the brush is spring-loaded, so it constantly 'pushes' out against contact ring at one end, and the horn at the other, right?I think that's all I need to confirm. I still cannot figure out, given that I think I'm right about the circuitry from what Rarebits says, why the horn works fine with the horn resting on the boss - ie with all contacts as they should - but goes constantly with the horn pushed in, when all the contacts should be exactly the same. Perhaps the brush really is butted up too close to the wheel so it's 'skewing' and contacting the boss, bypassing the horn altogether and closing the circuit.Time for some detective work. Thanks for the help. Link to comment Share on other sites More sharing options...
CharlieB Posted July 9, 2011 Share Posted July 9, 2011 Yes, yes & yes :) (By horn I assume you mean horn button) Link to comment Share on other sites More sharing options...
Brendan The Spit Posted July 9, 2011 Author Share Posted July 9, 2011 OK, all sorted! The metal bit sticking out the back of the horn was too short so I'd extended it, but I think I'd gone too far with that. So I just cut it back down, played around with positioning, and now it's done.And the steering wheel is straighter.And I went out and bought some gasket paper and made a proper gasket for the fuel pump rather than a cornflake packet.And I replaced one of the pipes while I was at it cos it looked a bit old and cracked.And I bought some spare fuses, although the chap at the shop reckoned 17-amp fuses didn't exist. But that's what I have in the Spit. I got some 15 amp fuses but might have to shop around. But that's another story...CheersB Link to comment Share on other sites More sharing options...
BrendanD Posted July 9, 2011 Share Posted July 9, 2011 well done! Link to comment Share on other sites More sharing options...
Brendan The Spit Posted July 9, 2011 Author Share Posted July 9, 2011 Ta :) Link to comment Share on other sites More sharing options...
saffie Posted July 27, 2011 Share Posted July 27, 2011 I have the opposite problem. I've just got a Mountney Steering Wheel and Boss, and fitted the wheel but the horn won't work. I think the pencil thing isn't contacting the contact on the new horn push, and its also not earthing down the column.Any ideas to get around these problems? Link to comment Share on other sites More sharing options...
willcolumbine Posted July 27, 2011 Share Posted July 27, 2011 I managed to get my Mountney boss working by drilling out the rivet holding in the crimp connector on the back and fitting a strip of steel to contact the horn 'pencil'. There are a few pics on my blog somewhere I think. It works great but you do need to line it up carefully and wrap a bit of tape around the inside edge of the boss - otherwise the force of the spring in the pencil bit will pop the horn push off now and then! Link to comment Share on other sites More sharing options...
Velocita Rosso Posted July 27, 2011 Share Posted July 27, 2011 1486 wrote:I have the opposite problem. I've just got a Mountney Steering Wheel and Boss, and fitted the wheel but the horn won't work. I think the pencil thing isn't contacting the contact on the new horn push, and its also not earthing down the column.Any ideas to get around these problems? ..and the earth is : down the column, bridging the steering uj with an earth , braided wire then an earth wire from st/rack to chassis Link to comment Share on other sites More sharing options...
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