* Check the bulbs: This is the most common cause. Remove the brake light bulbs and visually inspect the filaments. Even if they seem fine, test them with a multimeter (if you have one) to be sure they're not drawing current. Replace any burned-out bulbs.
* Check the sockets: Examine the bulb sockets for corrosion, broken contacts, or loose connections. Clean any corrosion with a wire brush and reconnect any loose wires.
* Check the brake light switch: This switch is usually located near the brake pedal. It activates when you press the brake pedal. You may need to test this with a multimeter to see if it's closing the circuit when the brake pedal is depressed. A faulty brake light switch is a common cause of brake light failure.
* Wiring: There might be a break in the wiring running from the brake light switch to the brake lights. Carefully inspect the wires for any damage (cuts, chafing against metal) between the switch and the lights.
* Grounding: Poor grounding can also prevent the brake lights from working. Inspect the ground wires connected to the brake light assembly for corrosion or loose connections. Ensure a good ground connection.
Important Safety Note: Always disconnect the battery's negative terminal before working on any electrical components in your vehicle.
If you're uncomfortable performing these checks, it's best to take your Silverado to a qualified mechanic for diagnosis and repair. Trying to diagnose electrical issues without the proper tools and knowledge can be dangerous.
