Jeep Wrangler Third Brake Light Not Working: A Troubleshooting Guide

The brake light functions when it receives power from the pedal of the brake switch. Thus, it alerts people behind you. It’s also known as the center high-mounted stop lamp (CHMSL). But sometimes the 3rd brake light stops working, which hampers your safety on the road.

So why is your Jeep Wrangler third brake light not working? 

• A blown fuse
• Defective bulb
• Loose or damaged wire connections
• Faulty switches, etc., can be the chief causes behind this particular problem.

Fortunately, solving these issues isn’t rocket science. If you have some expertise in fixing wire-related issues, you can fix this problem too. Read along to discover more possible reasons with their easy solutions.

1 Minute Quick Overview on Jeep Wrangler Third Brake Light Not Working 

Here’s a quick review of the common problems with their solutions:

Issues	Solutions
Dust and debris	Clean the area
Blown Fuse	Replace the fuse
Defective Third Brake Bulb	Replace the defective part
Loose Connection	Inspect and secure the connection
Frayed or Damaged Wires	Fix with new wires
Defective Switch of the Brake Light	Need replacement
Corrosive Parts	Remove corrosion
Faulty Body Control Module (BCM)	Consult with professionals

Possible Reasons Behind Jeep Wrangler Third Brake Light Not Working with Their Solutions

You’ll find multiple reasons behind the Jeep Wrangler 3rd brake light not working issue. Some of the most common causes and their solutions include:

Dust and debris

Dust and debris can accumulate on the bulb or wiring harness of the brake light when you are running your vehicle and not cleaning at all. This issue can lead to a poor connection that prevents the brake light from functioning properly.

Solution

The basic solution is to clean the brake light and surrounding area to remove dust and debris buildup. The cleaning process is —

1. Turn your vehicle engine off and remove the key.
2. Open the rear door of your vehicle and locate the brake light. It should be near the top center of the rear spare tire carrier.
3. Gently remove the bulb from the socket by twisting it counterclockwise.
4. Now clean the wiring harness, bulb, and surrounding area with a soft brush, cotton cloth, or compressed air. 
5. After that, reinstall the parts you’ve taken out and test the brake light.

Blown Fuse

This issue is often the primary culprit when a third brake light starts malfunctioning. The fuse is designed to protect electrical circuits from high electrical flow. It’s usually located under the dashboard or in the engine compartment.

Overloading the power surge, short circuits, defective electric devices, overheating, or worn-out wires are the main reasons behind a blown fuse.

Solution

To check whether the fuse is the issue, locate the fuse labeled for the 3rd brake light and inspect it for damages or a blown filament. If you find the fuse is blown, replace the defective fuse with a fuse that functions at a similar amp rating. 

Here’s how to replace it:

1. First, find the fuse related to the light from the fuse diagram or owner’s manual.
2. After you find it, turn off your vehicle’s engine and remove the key.
3. Take out the blown fuse from the socket using a fuse puller tool.
4. Now insert a new fuse with the same amp rating and push it until you hear a click sound.
5. After setting up the new fuse, check whether the brake light works.

Check this YouTube video for further guidelines in this regard

Defective Third Brake Bulb

If the fuse is not the problem, it’s likely that the bulb is burnt out. Over time, the bulb can wear out and require replacement. Overheating and wear on the bulb are two main reasons behind a faulty third brake bulb.

Solution

To change the bulb, you need to access its location. The brake should be near the rear hatch or tailgate. Here’s how to change:

1. First, remove the housing cover and inspect the bulb for damages or broken filaments. 
2. If the bulb is faulty, replace it with one specifically designed for your Jeep Wrangler model.
3. Close the housing cover and check the light.

Check out this video for visual guidelines

Loose Connection

The entire function of a vehicle is through sensors and wiring connections. So when a wire related to the light isn’t connected properly, the brake light will fail to receive commands and work functionally.

Solution

The simple solution is to ensure proper wire connections.

1. First, turn off your vehicle, access the brake light area, and thoroughly inspect the connection.
2. Ensure a secure connection between the bulb, wiring harness, and the direct wire from the pedal (ground wire).
3. After inspecting, close the covers and check the brake light.

Frayed or Damaged Wires

Besides loose wiring connections, frayed, damaged, or worn-out wires are other common reasons. 

Over time, the constant movement and vibrations of the vehicle can cause the wires to rub against each other, components, or sharp edges. This friction can lead to insulation damage and wire fraying.

Moreover, exposure to extreme heat is also a culprit behind this issue.

Solution

Here’s the process of replacing damaged wires:

1. Gather the required tools like wire crimpers, strippers, electrical tape, etc.
2. First, disconnect the negative terminal of the vehicle’s battery.
3. Now search for worn-out, fraying, or damaged wires in the wiring harness for the brake light.
4. When you locate the damaged area of the wires, cut it out using wire cutters. Leave enough length on each side while cutting to connect the new wires.
5. Remove a small insulation section from the ends of the old wires using wire strippers.
6. Connect the new wires and secure them with electrical tape. 
7. Use a heat gun to shrink and insulate the new connections.
8. Reinstall the parts you’ve opened.
9. The final step is testing the brake light.

Defective Switch of the Brake Light

The switch of the brake light is an essential component that activates the brake light when you press the brake pedal. When the switch is faulty, the brake light may not function. 

Solution

Here’s how to fix this issue:

1. The switch should be near the pedal, above the arm. Remove the lower dashboard panel to access it.
2. Disconnect the battery and wiring harness (make sure you take note of the wire color order).
3. Use a socket wrench to lose the nuts and remove the brake switch.
4. Install the new third brake switch and secure it in place.
5. Reconnect the wiring harness, battery, and lower dashboard.
6. Test the new switch and check if the light is on.

Corrosive Parts

Over time, corrosion can build up on the wiring harness or connectors. It eventually causes a weak connection or even a complete failure of the 3rd brake light. 

Solution

To fix this issue — 

1. You need sandpaper or a wire brush to remove corrosion from the surface. Keep sanding until the corrosive area is clean.
2. Apply dielectric grease to the connectors to prevent future corrosion (optional).

Faulty Body Control Module (BCM)

A Defective Body Control Module (BCM) can also be the reason for a malfunctioning third brake light. The BCM controls various electrical functions in a vehicle, including the brake light. If the BCM is not sending the proper signals, the brake light may not activate. 

Solution

Diagnosing and resolving BCM issues requires advanced diagnostic tools and expertise. That’s why it’s wise to consult a qualified technician or your Jeep dealership to solve BCM problems.

If you’re a Jeep Wrangler owner facing a non-functional third brake light, our article on brake light not working after changing the bulb might provide insights that could assist in resolving your issue. Furthermore, if you’re dealing with an ABS light issue in your Dodge Grand Caravan, our guide on Dodge Grand Caravan ABS light on concerns may offer valuable solutions. We recognize the importance of maintaining proper vehicle lighting and addressing any issues that may arise, and our comprehensive resources are aimed at helping you navigate and resolve challenges you may face.

FAQs

Here are some common questions we often receive from people:

Conclusion

So you now know why your Jeep Wrangler third brake light not working. Remember to start with basic troubleshooting steps, such as checking the fuse and the bulb, as a small issue can be the main reason. 

If you have tried all the mentioned solutions, your Jeep may have more complex issues that need a professional hand. Plus, when you find the fixing solution tricky, kindly contact a certified mechanic to seek help.