One component that is common among vintage car models is its electric car horn. This type of horn has been used since the early 1900s and it’s cool to retain them in your classic car. Its unique sound quality is what really makes it great!
Retaining the original, vintage car horns in your vehicle requires that you know its basic operation, diagnostic tips and other essential things to its common problems.
What are the different types of horn?
Through the years, the shape and size of car horns have changed drastically. Older models, those built around 1930s, like the MG TC Series Roadster are installed with a 12-inch, trumpet style car horn. The horns look much like the trumpets and saxophones you can see at http://windplays.com/. Later models produced during the 60s era carry a snail shell – a more compact vintage car horn. But regardless of the horn design, the horns are usually mounted just behind the grille giving it a prominent location on the vintage car’s frontage.
Perhaps, the most radical technical change was when the horn button was relocated from the dash to the steering column. Being close to the driver’s hands, the horn is much easier and faster to activate.
Car horns have also transformed from single to a dual set up. This major upgrade ensured a backup in case one of the horns failed, at the same time, offered a diversity of sound with two distinctive sound frequencies produced by each horn. Moreover, having two different tones has increased the loudness slightly but has a great impact on human recognition of the warning noise.
How horns work?
Although much has changed with the looks of horns, the most basic mechanisms are still much the same. Horns work by energizing an electromagnet that operates a thin steel diaphragm built into snail shaped amplification housing. A lot of horn models will have an adjustment screw which changes the distance between the diaphragm and the electromagnet to achieve desired sound quality.
How the sound device is powered vary depending on the model, make and year of the horn. The basic operation uses the contacts mounted onto the steering wheel. When the horn button is depressed, the contacts close allowing the batter voltage to run to the relay. Since the steering wheel changes position while the column does not, it’s important to use a contact brush and ring to ensure voltage flow regardless of the position of the steering wheel.
Once the voltage reaches the horn relay, the magnetic coil inside is powered up which then closes the contacts and the sound device is activated. This mechanism is used since the horn circuits can gobble up a lot of amperage. Usually, the horn can draw around 5-9 amperes – which makes a power-hungry automobile part.
Checking vintage car horn problems
Locating malfunctions with vintage horns is fairly easy – thanks to its simple circuitry. However, an assistant comes very handy to push on the horn button while performing the tests. When checking the sound device, the first to check is the power source and the ground. While the horn button is pressed, use a multimeter or test light to check if there is power.
If the sound device does not have power, you can check the fuse if it’s busted. If the fuse is okay, then check the relay if power is passing through it. Malfunctioning horn relays is also a common problem in vintage car horns. If power doesn’t reach the relay from the steering column, then check the brush and slip ring or the horn contacts.
If there is a good power and ground at the car horn, yet it doesn’t honk or responds poorly, check to see if there is damage or corrosion inside the thin metal diaphragm. Expect problems to be more common among older automobiles. If you are unable to troubleshoot the problem, you can bring your vintage car to a car repair shops specializing in classic cars restorations. These folks could help solve your vintage car horn problems.