Jeep DJ-3 Brake Light Switch Guide (1959-1966)
Keep your classic DJ-3 safe and legal by troubleshooting and replacing your brake light switch.
- The brake light switch on a DJ-3 is a simple hydraulic pressure switch located on the master cylinder, not on the pedal.
- Failure symptoms are straightforward: brake lights don't work, or they stay on constantly.
- Replacement is a very easy DIY task that usually takes less than 15 minutes.
- Quality aftermarket brands like Standard Ignition and Crown Automotive are the best and only practical options for a new part.
Symptoms of a Failing Brake Light Switch
On a vintage vehicle like the DJ-3, the signs of a bad brake light switch are straightforward. The electrical system is simple, making it easier to diagnose problems compared to modern vehicles. Look out for these key symptoms:
- Brake Lights Don't Turn On: This is the most common and dangerous symptom. If your bulbs and fuses are good, the switch is the next most likely culprit.
- Brake Lights Stay On: The switch can fail in the 'on' position, causing your brake lights to remain lit even when you're not braking. This can drain your battery and confuse other drivers.
- Intermittent Brake Lights: The lights may flicker or only work when you press the pedal very hard. This often points to a worn-out switch that is about to fail completely.
Pro Tip: Easy Diagnosis
Before replacing the switch, you can perform a simple test. Disconnect the two wires from the switch and touch them together (with the ignition on). If the brake lights illuminate, the switch is faulty and needs to be replaced. Also, always check for bad grounds, which are a common source of electrical issues on older vehicles.
Choosing the Right Aftermarket Switch
Finding a new original equipment (OEM) brake light switch for a vehicle from this era is nearly impossible. Fortunately, the aftermarket provides reliable and affordable replacements that meet or exceed original specifications.
For your 1959-1966 DJ-3, you will primarily find parts from these brands:
- Standard Ignition (SMP): A well-regarded brand in the aftermarket industry. Their switches, like the SLS-118 or SLS-27, are often made with durable brass housings and copper conductors for longevity. They are known for being reliable, direct-fit replacements.
- Crown Automotive: Specializing in Jeep parts, Crown offers a direct replacement switch (part number J0647801) specifically for 1941-1966 Jeeps, including the DJ-3. They are a go-to source for many classic Jeep owners.
Given the simple mechanical nature of this part, both Standard and Crown are excellent choices. The quality difference between a new aftermarket switch and a non-existent new OEM part is not a concern here; a quality aftermarket part is the correct and only practical choice.
Estimated Costs
| Part Type | Price Range |
|---|---|
| New Aftermarket Switch | $10 - $16 |
| Shop Labor | $50 - $100 |
Note: Prices are estimates and may vary based on location and supplier. The job is simple enough that most owners can avoid labor costs.
No Recalls or TSBs for This Model
While you may find information about brake light switch recalls for modern Jeeps, these do not apply to the 1959-1966 DJ-3. Your vehicle uses a simple hydraulic switch, which is not related to the complex electronic systems in newer models that have been subject to recalls.
Frequently Asked Questions (FAQ)
Where is the brake light switch located on my DJ-3?
The brake light switch is not located by the pedal. It is a pressure switch that screws directly into the front of the master cylinder under the hood.
Is replacing the brake light switch a difficult job?
No, this is a very easy DIY job. It typically involves disconnecting two wires, unscrewing the old switch, and quickly screwing the new one in. The entire process can take as little as five to ten minutes.
Will I need to bleed my brakes after replacing the switch?
If you are quick when swapping the switches, you will only lose a drop or two of brake fluid and will likely not need to bleed the brakes. However, if you let a significant amount of fluid leak out or air enter the system, a proper brake bleed will be necessary. It's a good idea to have a rag ready to catch any drips.
What tools do I need to replace the switch?
You will typically only need a wrench that fits the hex-shaped body of the switch. No special tools are required.
Technical Specifications
OEM Part Numbers: J0647801
Hydraulic pressure-activated switch, 2-terminal, screws into master cylinder.
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.