BMW M6 (1987-1988) Horn Replacement Guide
Restoring the powerful, dual-tone sound of your classic M6 starts with understanding how the system works and what commonly fails.
- The 1987-1988 M6 uses a dual-horn system (high and low tone); replace in pairs for best results.
- Always check the fuse (#7) and relay (K2) before assuming the horn units themselves are bad.
- Common failure points include the horns themselves, the relay, steering wheel contacts, and corroded grounds.
- Aftermarket brands like Standard Ignition offer a quality replacement, while 'Replacement' brands are a budget-focused option.
Symptoms of a Failing Horn
On the E24 M6, horn problems aren't always straightforward. Because it's a system with several parts, the symptoms can point you to the specific failed component.
- Completely Silent Horn: If nothing happens when you press the horn button, the most likely culprits are a blown fuse, a bad horn relay, or a problem in the steering wheel's contact system.
- Weak or Raspy Sound: If the horn sounds weak, muffled, or "sick," it often means one of the two horns (high or low tone) has failed. It can also be caused by corrosion on the electrical connectors or a poor ground connection where the horn bolts to the chassis.
- Horn Works Intermittently: An intermittent horn is often a sign of a failing relay or a loose connection in the steering column's slip ring or horn button contacts.
- Horn Won't Stop Blaring: While rare for the main horns, some E24 models have a separate horn for the security system/OBC that can fail and sound continuously. If your main horns are stuck on, it usually points to a shorted relay or horn button.
Pro Tip: Diagnose Before You Buy
Before buying new horns, test the system. A common trick for E24 owners is to swap the horn relay (labeled K2 in the fuse box) with an identical relay, like the one for the fog lights (K8). If the horn starts working, you just need a new relay. You can also use a jumper wire at the relay socket to send power directly to the horns; if they sound, the problem is with the relay or the steering wheel controls, not the horns themselves.
Choosing the Right Aftermarket Horn
For a classic like the M6, you have a few options. Since these cars have a high and low tone horn, you must replace the failed unit with the correct tone or replace both as a matched set for the best sound.
| Brand Tier | Our Brands | Description & Quality Assessment |
|---|---|---|
| Standard Replacement | Standard Ignition | Standard Motor Products (SMP) is a well-regarded aftermarket manufacturer known for producing parts that meet or exceed original equipment specifications. Their horns are considered a reliable, direct-fit replacement that will restore the original sound and function. This is a solid choice for owners who want quality without paying for a premium brand name. |
| Value Option | Replacement | "Replacement" is a budget-friendly option. While it will get your horn working again, the tone and long-term durability may not be on par with the original BMW horns or higher-quality aftermarket brands like Standard Ignition. This is a practical choice if the primary goal is to pass a safety inspection on a budget. |
Known Issues, Recalls, and Service Bulletins
There are no specific recalls or Technical Service Bulletins (TSBs) from BMW or the NHTSA regarding horn failure on the 1987-1988 M6. However, owner forums for the E24 chassis are full of discussions about horn issues, confirming that failures of the relay, fuse, and the horn units themselves are common over the life of the vehicle.
Frequently Asked Questions (FAQ)
Do I need to replace both horns at the same time?
You don't have to, but it's recommended. The original horns have aged together. Replacing them as a pair ensures a correct, strong tone and prevents you from having to do the job again in a few months when the other old horn fails.
Is the horn difficult to replace on an M6?
The replacement itself is easy; the horn is held by one nut and has a simple electrical plug. The main difficulty is access. The horns are located behind the front bumper, so you may need to remove the bumper cover for easy access, which makes the job more involved.
Could the problem just be a fuse?
Yes. Always check the fuse first. On the E24, the horn circuit is often protected by fuse #7. It's the easiest and cheapest potential fix.
What is a horn relay and where is it?
The relay is an electronic switch that uses a low-power signal from your steering wheel to control the high-power circuit for the horns. In the E24 M6, the horn relay is typically found in the main fuse box and labeled as K2.
Technical Specifications
OEM Part Numbers: 61331371914
System Type: Dual Horn (High-Tone & Low-Tone) Voltage: 12V Common Relay Location: Fuse Box, K2 Common Fuse Location: Fuse Box, #7
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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