* Bulbs: This is the most common cause. The bulbs themselves may have simply burned out. Check all bulbs (brake lights, turn signals, running lights) in both tail light assemblies. Replacing them is relatively easy and inexpensive.
* Fuses: A blown fuse in the fuse box can cut power to the tail lights. Consult your owner's manual to locate the fuse box and identify the correct fuse(s) for the tail lights. Replace any blown fuses. If a fuse blows repeatedly, there's a short circuit somewhere in the system, which requires further investigation.
* Wiring: Damaged or corroded wiring can interrupt the electrical connection to the tail lights. Check the wiring harness for breaks, chafing, or corrosion, particularly near the tail light assemblies and where the wiring enters the vehicle's body. This often happens near the trunk hinges.
* Tail Light Assembly: Sometimes, the problem lies within the tail light assembly itself. There might be a faulty connection inside the housing. Carefully inspect the assembly for any loose or broken internal wiring or connectors.
* Wiring connector: Inspect the connection between the car and the tail light assemblies for corrosion or broken terminals. Clean and tighten connections or replace the connectors if needed.
* Switch (Brake Light Switch): A faulty brake light switch will prevent the brake lights from working correctly. This will need to be diagnosed and replaced by a mechanic or yourself if you are mechanically inclined.
* Multi-function switch (Turn signals, hazards): A faulty multi-function switch can affect the turn signals integrated into the tail light assembly and the hazards. Again, requires professional diagnosis and repair.
* Ground: A poor ground connection can affect the entire tail light system. Check the ground points for the tail lights and ensure they are clean and secure.
Troubleshooting Steps:
1. Start with the simplest: Check the bulbs first.
2. Check the fuses: Consult your owner's manual to locate the correct fuses.
3. Visual Inspection: Examine the wiring harness for any visible damage.
4. Test the brake light switch: You can have someone press the brake pedal while you check if power is reaching the brake lights.
5. Professional Help: If you're not comfortable working on car electrical systems, take your Malibu to a mechanic for diagnosis and repair.
Remember safety first! Disconnect the battery's negative terminal before working on any electrical components in your vehicle.
