Horn not working

When this happened to me a few years ago the problem was on the horn button itself--I don't recall the details, but lift off the button and look at the wire connection there.

 

First and foremost I would suggest checking to see if the horn itself is getting power when you press the horn button. The horn compressor is located next to the battery and is fed by a thick white wire. Especially if you do not oil the compressor they are known to go bad. I suspect that if you heard a little bit of noise that the compressor is on the way out and further pressings of the button maybe created a resistance to pop the fuse.

The horn circuit itself is very simple and the horn is fed by a relay labeled 'Fiamm' that is made of black plastic and on the fuse panel. If the first test does not show power going to the motor assuming the fuse is good, then the relay might be bad. Between the horn button, the relay, and the compressor there is not much else to go bad.

 

When that happened to me it turned out to be a poorly lubed compressor. Bit of oil and it started working fine.

 

I did a bit of research and it appears that one needs only a few drops of light machine oil to lubricate their Fiamm air horn compressor motor.

A bit more research suggests that Marvel Mystery Oil will do the trick. They make an air tool oil that looks particularly well suited for this application.

Check out ::Marvel Mystery Oil:: for details.

I'm going to give this a try and see if it boosts my air horns a tad.

Cheers,

Keith

 

As Nuvolari said:

Had the problem, that we forgotten to lubricate the compressor.

The current was that hight, that the fuse burnt. After rebuilding and some Oil in the compressor, everything was fine!

 

Here are some photos of the inside of the horn compressor:

Dino 246 Restoration Blog: Giving Dino a voice. The horn restoration

For the best result I would remove the compressor, take off the lid and check the main bore and vanes to ensure they have no corrosion and move freely. It is important to note that these compressors take only A FEW DROPS of oil. The oil soaks a sponge that deposits light amounts of oil to the moving parts.

 

I think that if you remove the battery cover you will be able to access it. I had this done on one of my Dinos a number of years ago. Fred

 

The compressor is a likely suspect but two others should be considered.

I have found the above and also and another which is much easier to check from the driver's seat.

1) Horn ground - as above, pull the steering wheel Dino horn push and check those side rails which contact the inner diameter of the steering column to make a circuit ground. This is the end of the "electrical chain" and if they're not contacting well or dirty then the horn may not honk.

2) Broken wire in steering column - the contact wire threads up through the center of the steering column to the horn push button. With each turn of the steering wheel that wire is twisted and then untwisted - the same repetitive motion which typically breaks wires over time. As Rob said, check the voltage at the wire but I'd like to add that you should twist it back and forth to see if it maintains 12-13V.

Hope this helps, I love my Dino air horns, so much character!

 

This is not actually correct. The wire in the steering column runs through the column, pops out at the base and is fixed via a ring terminal. When the column is turned the wire turns with the column and is not being twisted inside of it.

What makes the contact between the column and the rest of the circuit is a carbon tipped spring loaded brush that touches a machined brass cylinder that is at the base of the column. This allows for the assembly to turn without stressing the wire. A quick look under the column without any dis-assembly will reveal this brush assembly.

Perhaps the easiest test is to remove the horn button and touch the wire to the edge of the steering wheel hub. If there is no voltage at the horn motor, work your way to the brush, then the relay (always checking the fuse first).

 

All very handy....

Hopefully, I too can get my horn working!

 

Thanks, you're right of course ... unless you count a prior owner's dubious attempt at repair!


Imagine, the 40 yr old Dino has slip rings

 

Don't forget Rob/Paul have that original set for sale at far cheaper.

I'd still do the easy test first and pull the horn button, test that your're getting 12V there and inspect the ground for resistance. A minute or two well spent

 

Info on horn lube [ that sounds wrong, but you know what i mean]
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