Silverado Third Brake Light Not Working

Silverado Third Brake Light Not Working: Here’s How To Fix It

Silverado third brake lights are crucial for both your safety and the well-being of the driver behind you. If it is not functioning properly, it can pose a safety risk and may result in a traffic violation. Hence, identifying the reasons behind this issue and taking action is crucial. 

So why is the Silverado third brake light not working? The possible reasons are a blown fuse, a malfunctioning brake light switch, or just faulty bulbs inside the third brake light. Faulty brake sensors and loosened or damaged wirings can also be the case. Most of them can be fixed by replacement.

Knowing just the names of the problems certainly isn’t enough to diagnose those issues. We will go in-depth with the causes and provide an effective solution. Let’s get started.

Table: Silverado Third Brake Light Not Working

Silverado Third Brake Light Not Working

Before we go deep with the problems, let’s check out a table summarizing all the causes and solutions.

Blown FuseTake out the old brake light fuse from the fuse box using a fuse puller and replace it with a new one
Malfunctioning Brake Light SwitchDisconnect the battery and replace the brake light switch that is located near the top of the brake pedal assembly
Faulty Bulbs Inside The Third Brake LightRemove one bulb from the socket by twisting it anti-clockwise and replace it with a new one
Faulty Brake SensorsTry cleaning the sensors and if it doesn’t work, replace it
Damaged Or Loosened WiringsInspect all the wiring and connectors for damage and loosening and replace the faulty ones

Silverado Third Brake Light Not Working

This is the section where you will dive in deep with the causes and the solutions. 

Silverado Third Brake Light Not Working

Blown Fuse

The fuses help maintain a healthy current flow through the components. Thus, a blown fuse is a sign of the components being in working condition as the fuse has blown because an excess amount of current was flowing through it. 

Nevertheless, the third brake light also has a dedicated fuse that can blow. As a result, the third brake light might not be working.

Silverado Car Blown Fuse


In a Silverado, the fuse box is normally found in one of two locations: either inside the cabin or beneath the hood. The precise location could change depending on the Silverado’s individual model year and trim level.

  1. Before working with the fuse box, make sure that you have turned off the engine. 
  2. Now that you have located the fuse box look for a diagram on the inside of the fuse box cover or in your owner’s manual. You should look for the one that indicates which fuse corresponds to the third light or CHMSL. 
  3. Once you have found it, take the fuse out using a fuse puller tool and inspect for damage. A blown fuse will have a broken wire inside or a visibly melted appearance.
  4. If it is blown, replace it with a new one with the same amperage rating. 

Malfunctioning Brake Light Switch

The brake light switch completes the circuit between the third brake light and the brake. So when you depress the brake pedal, the brake switch is also activated, completing the brake circuit. As a result, the third brake light is illuminated.

Read:  Brake and Battery Light On: Possible Reasons and Solutions

So if the brake light switch is malfunctioning, the third brake light will not work. 


For this issue, you simply need to confirm whether the brake light switch is dead or not, and if it is dead, replace it. 

The brake light switch in a Silverado is typically located near the top of the brake pedal assembly.  

  1. You need to get access to the space underneath the driver’s side dashboard to find the brake light switch.
  2. Start by adjusting the driver’s seat to provide room for you to work comfortably. 
  3. Next, arrange yourself so that you can see and access the brake pedal assembly.
  4. Make sure to disconnect the battery from the switch first and then remove any necessary panels that come in the way. 
  5. Remove the old brake switch and inspect visually for any wear and tear. 
  6. Later on, check the brake light switch’s condition through a multimeter set to resistance mode. 

The multimeter will display a low resistance reading or beep if it’s in working condition. If you don’t come across any of these, you need to install the new switch and install everything back in place. 

Here’s a video that will help you on how to use the multimeter properly;

Faulty Bulbs Inside The Third Brake Light

The third brake light consists of several small bulbs. These bulbs glow together to provide you with a bright braking indicator. However, there’s a chance that the third brake light is not working because of faulty bulbs.

The probability of all the bulbs getting broken together is low, but it is still a probability. This mostly happens when there is an overload on these bulbs or a short circuit. 


You can already guess that the only way to solve this issue is by replacing the bulbs. 

  1. Start by turning off the vehicle and remove any screw from the brake light that holds the bulbs inside. 
  2. Now, carefully remove any covers that may be coming in the way. You only need to change one bulb to figure out whether it’s the bulbs that are causing the problem or not. 
  3. Simply twist one of the bulbs anticlockwise from the socket and install the new one by twisting it clockwise. Now, if the new bulb glows, try to replace it with other bulbs.

Faulty Brake Sensors

Before we get started, most people confused the brake sensor with the brake light switch. They are not the same component. The vehicle’s electrical system receives a signal from the brake sensors when the brake pedal is depressed. This signal causes the third brake light to turn on.

Therefore, a non-functioning brake sensor can cause the third brake light not to work as the sensors aren’t able to send the information. Now the question is whether the brake sensor is just dirty or broken. Let’s learn about it in the solution section.

Silverado Car Faulty Brake Sensors


The brake sensor in a Silverado can typically be found mounted on or near the brake pedal arm. 

  1. Start by visually inspecting the sensor, looking for any damage or dirt accumulation. 
  2. If it is dirty, try cleaning out the sensor and putting it back again to check whether the third brake light glows.
Read:  8 Causes Of Brake Light Not Working But Tail Light Works!

On the other hand, if it still doesn’t work, try connecting the brake sensor with a multimeter to find the resistance of the sensor. If it’s below the range of recommended resistance, it is damaged. You can find the recommended resistance in the user manual or specifications provided by the multimeter manufacturer.

Damaged Or Loosened Wirings

One of the most common reasons behind a third brake light not working is damaged wirings. Wires tend to get damaged over time or loosened, which can interfere with the connection of the third brake light. As damaged wires aren’t capable of conducting electricity, the lights also won’t work.

Silverado Car Damaged Or Loosened Wirings


The only solution here is to check each of the wiring that connects to the third brake light. This part can get tricky and require experience to figure out the non-functional wires as you have to dig quite deep through the wires. 

You can check the wirings through a multimeter and see if any resistance registers or not. Then you have to replace the damaged wirings. Whereas, for loosened wires, check the connectors properly to ensure none of the connection is loose.

Nevertheless, if you feel not so qualified, getting help from a professional is the right way to go.

If you’re facing an issue with the third brake light on your Silverado, our article on third brake light not working could offer solutions to help you resolve the problem. Moreover, if you’re concerned about whether you can pass a vehicle inspection with your ABS light on, our guide on can you pass inspection with ABS light on might provide the answers you’re seeking. We understand the importance of maintaining vehicle safety and compliance, and our comprehensive resources aim to assist you in addressing any issues you may encounter.


Let’s check out some commonly asked questions regarding the Silverado third brake light not working.

Q: Is it illegal to drive with the third brake light not working?

The illegality of driving a vehicle with a non-functioning third brake light depends on the state and country. For example, California and Texas require a functioning third brake light, whereas Florida and Nevada don’t. 

Driving laws vary significantly around the world, so you need to check with your local lawyer or the internet to confirm it. 

Q: Can water intrusion in the wires cause the third brake light not to work?

Yes, water intrusion in the wires can cause the third brake light not to work. Water can create a short circuit or disrupt the electrical connection, leading to a malfunction in the brake light system.

Q: How much does fixing a third brake light by a professional cost?

The exact cost of fixing the third break by a professional depends on the location and the replacement material. However, the range for fixing it would be around $50 to $200.


To conclude, you can solve most of the issues on your own when it comes to Silverado third brake light not working. Replacing the bulbs and the fuse is basic work and anyone can do it. Whereas fixing the brake sensor by cleaning it and replacing the brake light switch requires some amount of knowledge.

Lastly, inspecting and replacing the damaged wires is something that requires expertise. If you are new at it, it’s recommended that you don’t mess with it. It’s best if you hire a professional to go through it for a positive result.

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