Looking to add extra safety and style to your Jeep JL? Installing a spare tire brake light is one of the smartest upgrades you can make. This simple addition not only makes your Jeep more visible to drivers behind you but also keeps your vehicle street-legal after lifting or swapping tires. Many Jeep owners find that after changing their rear setup, the factory third brake light is blocked or removed. If you want to keep things safe (and avoid tickets), adding a spare tire brake light is a must.
This guide will walk you through the process, step by step. Whether you’re new to DIY car work or have some wrench time under your belt, you’ll learn what you need, common pitfalls, and some tips that most beginners miss.
Why Install A Spare Tire Brake Light On A Jeep Jl?
The Jeep JL is built for adventure, but modifications like larger tires or aftermarket bumpers can block or remove your stock third brake light. In many states, the law requires a visible center brake light. If you lose that, you risk getting pulled over or—worse—not being seen in traffic.
A spare tire brake light solves this by placing bright LEDs inside or around your spare tire, ensuring you’re always visible. These brake lights are often more noticeable than the factory version, especially at night or in bad weather.
Benefits At A Glance
- Improved safety: Extra visibility reduces rear-end accidents.
- Legal compliance: Stay on the right side of the law.
- Modern look: Clean, custom style for your Jeep.
- Easy installation: Most kits are plug-and-play.
What You Need Before You Start
Before you dive in, gather your tools and parts. This avoids frustration halfway through.
Essential Tools
- Socket set (metric and standard sizes)
- Wire crimpers/strippers
- Screwdriver set
- Pliers
- Electrical tape or heat shrink tubing
- Torx bits (Jeep uses Torx bolts in many spots)
Parts Required
- Spare tire brake light kit (make sure it fits Jeep JL, 2018+)
- Wiring harness (often included with the kit)
- T-tap connectors (if not splicing directly)
- Zip ties (for neat wiring)
Pro Tip: Not all kits are the same. Double-check compatibility with your tire size and wheel pattern before buying.
Example Popular Kits
- Rugged Ridge LED Brake Light Ring
- Mopar Official Third Brake Light
- Xprite Spare Tire Brake Light
Choosing The Right Brake Light Kit
Not every brake light fits every Jeep. Here’s a quick comparison of popular options for the JL:
| Brand | Fitment | Brightness | Warranty |
|---|---|---|---|
| Rugged Ridge | Fits up to 20″ tires | High (LED) | 5 Years |
| Mopar OEM | Factory sizes only | Medium (Halogen) | 2 Years |
| Xprite | 17–20″ tires | Very High (LED) | 1 Year |
What To Look For
- LED vs Halogen: LED is brighter, lasts longer, and uses less power.
- Fitment: Make sure the light ring fits your tire size and bolt pattern.
- Warranty: A longer warranty means the company trusts their product.
- Waterproofing: Off-roading means mud and rain—get a sealed light.
Non-obvious insight: Some cheap kits lack proper waterproof seals. This can cause flickering or failure after a few months. Spend a little more for a kit with a good IP67 or IP68 rating.
Step-by-step Installation Guide
This process takes about 1 2 hours. Set aside a little extra time if this is your first Jeep mod.
1. Remove The Spare Tire
- Use your socket set to remove the three lug nuts holding the spare.
- Lift the tire off and set it aside.
Tip: Place the lug nuts in a magnetic tray so you don’t lose them.
2. Prepare The Brake Light Ring
- Unbox your brake light kit.
- Test-fit the light ring against your spare tire carrier. The holes should line up with the wheel studs.
3. Attach The Light Ring
- Slide the light ring onto the wheel studs of the tire carrier.
- Some kits use spacers—install these if needed for larger offset wheels.
4. Route The Wiring
- Most kits come with a wire harness.
- Route the wires through the center of the spare tire carrier, following the factory wiring path if possible.
- Use zip ties to secure the wiring so it doesn’t hang or rub against sharp edges.
Non-obvious insight: Run the wires on the inside of the carrier, not the outside. This protects them from weather and off-road debris.
5. Connect To The Brake Light Circuit
- Locate the factory third brake light wires. These are usually behind the spare tire carrier, inside a plastic wire loom.
- Use wire strippers to expose a small section of the red (power) and black (ground) wires.
- Use T-tap connectors or splice the new wires directly into the factory wires.
- Secure the connections with electrical tape or heat shrink tubing.
Common mistake: Do not connect to the taillight wires—your new brake light will always be on. Only connect to the dedicated third brake light circuit.
6. Test The Light
- Have someone press the brake pedal while you observe the new light.
- The ring should light up only when the brake is pressed.
- If it does not, check your wiring connections and ground.
7. Reinstall The Spare Tire
- Carefully place the spare tire back onto the carrier, making sure not to pinch the new wires.
- Tighten the lug nuts securely.
8. Final Checks
- Use zip ties to tidy up any loose wires.
- Make sure the wiring does not touch hot or moving parts.
- Check that the spare tire sits flush and the light ring is visible.
Wiring Diagram: Simple Reference
Here’s a basic wiring comparison for Jeep JL brake light installation:
| Wire Color (Factory) | Function | Connect To |
|---|---|---|
| Red/White | Brake Light Power | Brake Light Ring (+) |
| Black | Ground | Brake Light Ring (–) |
Some kits have extra wires for turn signals these are not needed for basic brake function.
Practical Tips And Tricks
- Test before final assembly: Always check the light ring works before putting everything back together.
- Use dielectric grease on connections to prevent corrosion.
- Check local laws: Some areas require a certain size or brightness for brake lights.
- If you off-road often, check the wiring after each trip for damage.
Real-world Example
A Jeep JL owner in Colorado installed a Rugged Ridge LED ring after upgrading to 35" tires. The light was visible even in dusty conditions, and he passed state inspection with no issues.
He noted that using heat shrink tubing on all connections avoided water damage after river crossings.
Troubleshooting Common Problems
Even with careful work, things can go wrong. Here are quick solutions to frequent issues:
- Light doesn’t turn on: Double-check ground connection and wiring polarity.
- Light is dim: Possible bad ground or poor connection; clean terminals and reconnect.
- Flickering: Wires may be loose, or there’s water in the connection.
- Brake warning light on dash: This usually means a wire short. Inspect for pinched wires behind the tire.
Cost And Value
Most spare tire brake light kits for Jeep JL range from $40 to $120. Professional installation can add $50 $100.
Doing it yourself saves money and builds confidence for future upgrades.
Cost Breakdown Example
| Item | Average Price |
|---|---|
| LED Brake Light Kit | $60 |
| Wire Connectors & Tape | $10 |
| Mechanic Labor (optional) | $75 |
Tip: Many Jeep clubs offer help with installs—often for free or a donation to a charity.
Maintenance And Longevity
LED brake lights usually last over 50,000 hours. Check wiring every oil change for signs of wear or corrosion.
If you notice dimming or flicker, clean and reseal the connections.
Legal And Safety Considerations
The third brake light is required by law in the United States for all vehicles after 1986. Failing to have one can lead to fines or failed inspections. Always install a light that is DOT approved. Check your state’s Department of Transportation website for exact requirements.
For more on federal rules, see the NHTSA Lighting Equipment Standards.
What Size Light Ring Fits The Jeep Jl?
Most JL kits fit 17 20" tires. Check your spare’s exact size and bolt pattern before ordering.
Some rings are adjustable for different wheel styles.
Do I Need To Drill Holes For Installation?
No, most quality kits are fully bolt-on and use existing wheel studs. Drilling is rarely needed unless you have a very custom tire carrier.
Will Adding A Brake Light Affect My Jeep’s Warranty?
No, as long as you do not cut or damage factory wiring. Using T-tap connectors or plug-and-play harnesses is safe.
Always keep original parts in case you need to return to stock.
Can I Install The Light Myself If I’m A Beginner?
Yes! Most Jeep JL owners with basic hand tools can complete the install in about an hour.
Take your time and follow the steps above.
How Do I Keep The Wiring Safe From Off-road Damage?
Route wires inside the tire carrier and use zip ties to secure them. Cover connections with heat shrink tubing.
After muddy or rocky trips, inspect for any wear or loosening.
Upgrading your Jeep JL with a spare tire brake light is a smart, simple project that pays off in safety and peace of mind. With the right kit and careful installation, you’ll enjoy better visibility and keep your Jeep both legal and stylish—on or off the road.
