Austin Eight Horn & Trafficator Switch Woes

Dealing with a malfunctioning horn and trafficator switch on a classic car can be a frustrating experience, especially when preparing for an MOT or simply aiming for proper functionality. This common issue, particularly prevalent in older vehicles like the 1940 Austin Eight, often stems from the intricate workings of these combined control units located in the centre of the steering wheel. The delicate nature of vintage components, coupled with age-induced fragility, can lead to a cascade of problems, from intermittent operation to complete failure. Understanding the potential causes and the correct procedures for diagnosis and repair is crucial for any classic car owner.

Understanding the Austin Eight Horn & Trafficator Switch Assembly

The horn and trafficator (turn signal) switch on many classic cars, including the Austin Eight, is often a combined unit housed within the steering wheel boss. Its purpose is to provide both audible warning and directional indication to other road users. The mechanism typically involves a central push button for the horn and a lever or rotary action for the trafficators. Internally, these switches rely on a series of electrical contacts that can become worn, corroded, or contaminated over time. The entire assembly is usually connected via a stator tube, which guides the wiring from the steering column to the switch mechanism.

Common Causes of Failure

Several factors can contribute to the failure of these vital switches:

• Contact Contamination: This is perhaps the most frequent culprit. Dust, dirt, oil, and oxidation can build up on the electrical contacts within the switch, creating resistance or preventing a complete circuit. This leads to intermittent operation, weak horn sounds, or trafficators that fail to illuminate or cancel correctly.
• Worn or Broken Contacts: Over years of use, the metal contacts can wear down, lose their spring tension, or even break, rendering the switch inoperable.
• Brittle Bakelite: The plastic components, often made of bakelite in older vehicles, can become extremely brittle with age and temperature fluctuations. This was a key issue for Stephen Fulcher, whose Austin Eight switch assembly disintegrated during an attempted removal.
• Wiring Issues: Loose connections, frayed wires, or internal breaks within the stator tube can also cause operational problems. The fluctuating voltage reported by Stephen suggests a poor or intermittent connection within the switch mechanism or its wiring.
• Mechanical Wear: The moving parts of the switch, including the lever or rotating components for the trafficators and the spring-loaded mechanism for the horn, can suffer from mechanical wear, leading to sticking or a lack of positive engagement.
• Incorrect Removal Attempts: As demonstrated by Stephen's experience, attempting to remove the unit without understanding its specific mounting mechanism can lead to accidental damage.

Diagnosing the Problem

Before attempting any disassembly, a systematic diagnosis is recommended:

1. Check Fuses and Wiring: Although less likely for a mechanical switch issue, ensure that the horn and trafficator circuits have proper power and that fuses (if applicable) are intact.
2. Test the Horn and Trafficators Directly: If possible, bypass the switch temporarily by connecting the relevant wires directly to power and earth (observing correct polarity) to confirm that the horn unit and trafficator bulbs/motors are functioning. This helps isolate the problem to the switch itself.
3. Inspect for Obvious Damage: Look for any visible signs of damage, such as cracked plastic, loose wires, or corrosion around the switch assembly.

Removal and Repair Strategies

Removing the switch assembly can be a delicate operation. The advice provided in the forum thread highlights several key points:

The Workshop Manual Method and its Pitfalls

Stephen Fulcher's workshop manual suggested loosening a lock nut on the end plate of the steering box and pulling the assembly out. However, the brittle nature of the bakelite meant the assembly came apart before it could be removed. This illustrates the importance of understanding the specific mounting of your vehicle.

Alternative Removal Techniques

• Grub Screws: As suggested by '47Jag', some steering wheels are secured by grub screws accessed through holes in the wheel's hub. Loosening these can allow the steering wheel itself to be removed, potentially providing better access to the switch assembly or revealing how it's secured. Stephen Fulcher later confirmed the presence of such holes on his Austin Eight's steering wheel, suggesting this might be a critical step missed in his initial attempt.
• Pinch Clamps: Some designs utilise a pinch clamp at the base of the steering column. Loosening this might allow the entire tube assembly to be withdrawn.
• Compression Fittings: Other designs employ a compression fitting, which often uses grub screws to secure the switch unit to the stator tube.

Securing the Unit

Rick, the site administrator, noted that on his Austin A40 Devon, a nut at the bottom of the steering box had to be undone to withdraw the switch and tube up through the column. This nut secured the threaded lower section of the stator tube. It’s possible the Austin Eight uses a similar, albeit perhaps shorter, arrangement.

Temporary Solutions for MOT

For owners needing to get their vehicle roadworthy for an MOT, Rick suggested setting up temporary switches for the horn and trafficators. This allows the vehicle to pass the inspection while the owner dedicates time to sourcing and fitting the correct, original parts without the pressure of immediate functionality.

Sourcing Replacement Parts

Finding original parts for classic cars can be challenging. The forum members offered several avenues:

• Autojumbles: These events are treasure troves for classic car parts, where individuals sell used and sometimes NOS (New Old Stock) components.
• eBay: Online marketplaces like eBay are excellent resources for finding obscure parts. Searching for specific part numbers or vehicle models (e.g., "Austin 8 horn switch", "Morris 8SE parts") can yield results. Rick even provided a link to an eBay seller who had previously supplied parts for a similar vehicle and mentioned availability of bakelite horn push assemblies.
• Specialist Publications: Advertising in classic car magazines or subscription papers, such as 'Classic Motor Monthly', can connect you with other enthusiasts or specialist suppliers.
• Vehicle-Specific Clubs: Joining an Austin Eight owners' club or a broader Austin car club can provide access to a network of knowledgeable members who may have spare parts or know where to source them.
• Interchangeability: As discussed, parts from contemporary models like the Austin Ten might be interchangeable, though differences in steering column length could affect the stator tube.

Internal Switch Repair

If the outer casing is intact but the contacts are dirty, careful cleaning might restore functionality. This typically involves:

1. Disassembly: Carefully dismantling the switch unit, taking note of the order and orientation of each component. Photographic evidence during disassembly is highly recommended.
2. Cleaning Contacts: Using a fine-grit sandpaper, a contact cleaner spray, or a pencil eraser to gently clean the electrical contacts. Avoid excessive abrasion.
3. Lubrication: A small amount of electrical contact lubricant can help ensure smooth operation and prevent future corrosion.
4. Reassembly: Putting the unit back together, ensuring all parts are correctly seated and the mechanism operates freely.

However, given the described damage to the bakelite on Stephen's Austin Eight, replacement is likely the only viable option.

Table of Potential Issues and Solutions

Frequently Asked Questions

Q1: My Austin Eight's horn switch is loose. What should I do?
A loose switch could indicate that the retaining mechanism (grub screws, pinch clamp, or nut) is not properly secured. Check the steering wheel hub for grub screws or the base of the steering column for a pinch clamp or nut, as described in the discussion.

Q2: Can I use a horn switch from a different Austin model?
It's possible, especially from contemporary models like the Austin Ten. However, be aware that the length of the internal stator tube might differ, which could affect fitment. Always try to confirm compatibility before purchasing.

Q3: Is it safe to try and pull the switch assembly out by force?
No, it's strongly advised against. As Stephen Fulcher discovered, vintage bakelite components are often very brittle and can easily break if excessive force is applied. Proceed with caution and ensure you have identified all securing mechanisms.

Q4: Where can I find detailed diagrams of the Austin Eight steering column?
Your best bet would be an Austin Eight workshop manual or an Austin 8 parts list. These resources often contain exploded diagrams that clearly illustrate how the components are assembled.

Q5: My MOT tester failed my car because the horn doesn't work. What's the quickest fix?
If time is critical, consider installing a temporary, robust toggle switch mounted discreetly on the dashboard or under the dash to operate the horn. This will satisfy the MOT requirement, and you can then address the original switch at your leisure.

Conclusion

Resolving issues with classic car lighting and signalling switches requires patience, a methodical approach, and often, a bit of detective work. The experience shared by Stephen Fulcher and the collective wisdom of the forum members highlight the common pitfalls and effective strategies for tackling these often fiddly repairs. By carefully identifying the securing methods, understanding the potential failure points, and exploring various parts sourcing options, owners can successfully restore the functionality of their Austin Eight's horn and trafficator system, ensuring both safety and authenticity.