BMW M5 (1988-1994) Brake Light Switch: A Complete Replacement Guide
Understanding and replacing the brake light switch in your classic E34 M5 is a simple but critical job.
- A faulty brake light switch is a critical safety issue that should be addressed immediately.
- Symptoms include non-working or stuck-on brake lights, cruise control issues, and a 'Brake Light Circuit' warning on the OBC.
- The correct replacement part for the E34 M5 is a 4-pin switch (OEM Part No. 61318360417).
- Replacement is an easy DIY job that takes about 30 minutes with basic tools.
Is Your Brake Light Switch Failing?
A faulty brake light switch in the E34 M5 is a common issue, but the symptoms are usually straightforward. Because the switch was subject to a recall in 1996, most cars have an updated part, but these can still fail over time. Look for these signs:
- No Brake Lights: The most obvious and dangerous symptom. The switch fails to complete the circuit, and the lights do not illuminate.
- Brake Lights Stuck On: The switch can fail in the 'on' position, keeping the brake lights illuminated constantly, which can drain your battery and confuse other drivers.
- 'Brake Light Circuit' Warning: Your M5's On-Board Computer may display a specific error message. This can happen if the secondary circuit in the switch fails, even if the lights themselves still work for a time.
- Cruise Control Malfunction: If the switch is faulty, it may not correctly signal the cruise control system to disengage, or it may prevent it from engaging at all.
A Note on the 1996 Recall
In October 1996, BMW issued a recall for the brake light switch on many models, including the 1990-1994 5-Series. The original switch design could fail, causing lights to stick on or not work at all. Dealers were to replace it with a switch using a more reliable contact system. While most cars should have the updated part, it's a 30-year-old component that can still wear out.
Choosing the Right Aftermarket Switch
For the E34 M5, you must use a 4-pin switch. Several aftermarket brands are available, falling into different quality tiers. Since this is a critical safety part, choosing a quality brand is recommended.
| Brand Tier | Brands | Our Take |
|---|---|---|
| OEM Supplier / High Quality | Hella, Febi Bilstein | These brands are often original equipment manufacturers for BMW and other German automakers. They offer the highest quality and best fit, making them a reliable choice for a critical part. |
| Quality Aftermarket | Facet, Vemo, Standard Ignition | These are reputable aftermarket brands that produce reliable parts. Facet is noted as an 'OE Equivalent' made in Italy. They offer a good balance of quality and price. |
| Budget Options | URO Parts, Rostra Powertrain | While functional, brands like URO Parts have a mixed reputation in the BMW community for fit and longevity. They can be an option if budget is the primary concern, but for a safety component like a brake switch, a higher-tier brand is a safer bet. |
Installation: A Simple DIY Job
Replacing the brake light switch is a straightforward task that most owners can do in about 30 minutes with basic tools.
- Location: The switch is located under the driver's side dashboard, mounted on a bracket near the top of the brake pedal arm.
- Access: You will need to remove the lower dash panel (kick panel) under the steering column to get to it. This usually involves a few screws.
- Removal: Disconnect the 4-pin electrical connector. The switch itself has a red locking sleeve. This sleeve must be slid out to allow the plastic tabs on the switch body to be compressed so it can be removed from its bracket. Some owners find it easier to break the old, brittle switch to get it out.
- Installation: With the red locking sleeve pulled out, insert the new switch into the bracket until it clicks. Then, slide the red sleeve in to lock it in place. Reconnect the electrical plug and test the brake lights before reassembling the dash panel.
Frequently Asked Questions
Where is the brake light switch located on a 1988-1994 M5?
It is located in the driver's footwell, mounted to a bracket above the brake pedal arm. You must remove the lower dash panel to see and access it.
Can I drive my M5 with a bad brake light switch?
No. If your brake lights are not working, it is a major safety hazard and illegal to drive on public roads. If they are stuck on, you risk draining your battery and confusing other drivers. This part should be replaced immediately.
Is this a difficult part to replace myself?
No, this is considered an easy DIY job for most home mechanics. It requires basic tools and about 30 minutes. The most difficult part is working in the tight space of the footwell.
Do I need a 2-pin or 4-pin switch?
The 1988-1994 E34 M5 requires the 4-pin brake light switch. Using a 2-pin switch from another model will not work correctly.
Technical Specifications
OEM Part Numbers: 61318360417 61311382385
Connector: 4-Pin
We Have This Part in Stock
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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