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French Horn

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jjbunn

jjbunn

Jedi Knight
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I was amused to find that the horn on my TR6 is a French Horn. It even has a metric (10mm) bolt that fits it to the bracket.

I had to take it apart as it wasn't working. At some point there had been water ingress, and so there was some rust. After cleaning that up and lubricating everything, and a bit of emery cloth on the points, it worked very well. In fact, when I tried it on the bench I almost jumped out of my skin.

It's a "grave" (low) note horn. The other horn is missing: I assume this would have been a high note horn. The wires to it were snipped bare off ... so I joined them and will make do with the single horn, which is quite loud enough.

In fact, to get the whole system to work, I had to remove the steering wheel (a major PITA), solder a new wire onto the brass contact ring piece (the old one had become detached, and was in any case too short) and thread it through the steering wheel cable tray ... some WD40 helped.

The horn looks original ... but maybe not. What brand of horn was usually fitted to TR6s - ClearHooters?
 
Julian,

Did you ever receive the speedometer cluster that I mailed to you? Just curious how long USPS takes coast to coast.
 
Brosky said:
Julian,

Did you ever receive the speedometer cluster that I mailed to you? Just curious how long USPS takes coast to coast.
Click to expand...

Not yet, Paul ... I'll ping you as soon as it does.
 
Julian: I have restored a number of these "hooters". The 250 has the same horns and I have had them apart many times. So many times in fact, that I don't depend on them operating reliably.
You may find that after a short time they will stop operating again. The problem seems to be the contacts tend to over heat and get pitted then they finally crap out completely.

I added a set of air trumpets many years ago and these never fail to get attention. You might want to consider doing the same as this is fairly a cheap solution, about $40., and seems to be a permanent fix. I suggest that you add a horn relay also.
 
angelfj said:
The problem seems to be the contacts tend to over heat and get pitted then they finally crap out completely.
Click to expand...
Might be amusing to try adding either a suppression diode or condensor across the points.
 
Small cars - Big horns. A good combination. I put air horns on mine after a little scuffle with a big truck - I don't think he heard my horn after he started drifting into my lane. Thank goodness small cars also maneuver well.
 
angelfj said:
Julian: I have restored a number of these "hooters". The 250 has the same horns and I have had them apart many times. So many times in fact, that I don't depend on them operating reliably.
You may find that after a short time they will stop operating again. The problem seems to be the contacts tend to over heat and get pitted then they finally crap out completely.

I added a set of air trumpets many years ago and these never fail to get attention. You might want to consider doing the same as this is fairly a cheap solution, about $40., and seems to be a permanent fix. I suggest that you add a horn relay also.
Click to expand...

My TR6 already has a horn relay. That surprised me, as I wouldn't think the current draw on a horn was enough to merit use of a relay (I measured about 2kOhms between the terminals). Anyway, the relay appears on Dan Masters' diagram, so it must be standard.

To clarify: I don't have a Clear Hooters horn, I have a French horn, I think the brand is MIZO.
 
jjbunn said:
My TR6 already has a horn relay. That surprised me, as I wouldn't think the current draw on a horn was enough to merit use of a relay (I measured about 2kOhms between the terminals).
Click to expand...
Something wrong, then. The average current draw isn't all that high (something like 5-10 amps, don't recall offhand), but the DC resistance of the coil is much lower than the average draw would indicate so should be less than 1 ohm. The average current is limited by the interrupting action of the points, and the inductance of the coil.

IMO, the reason for using a relay has more to do with the inductive kick from the coil than average current draw. It's the ensuing arc that burns and pits the switch contacts; the relays are made with extra contact area to withstand the arcing better.

Triumph added the relay at the TR4A (previous models didn't have one), then deleted it again for the TR250 and early TR6. Then they put it back again from about 70 onwards. Which explains why Frank's cars don't have one, but Julian's does. And I quite agree, it's a worthwhile addition to any car that doesn't have one already.
 
My Clear Hooters were goners when I bought this car. I went to Pep Boys (or some big box store) and bought a set of really loud Fiamm replacement horns. Look very similar to Clear Hooters in size and shape, install on the original brackets and accept OE wiring. And they will peel the paint off of any car in their way! High and low tone, they sound like an old Buick.

fiamm.jpg
 
I'm pretty sure it was 2kOhms ... and the coils were large, each about an inch high and half an inch in diameter, wound with fine wire ... which bears the measurement out.

The horn certainly works rather well :smile:
 
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