1. Bulbs:
* Check the bulbs: This is the most common cause. Start by checking both the brake light bulb and the taillight bulb on the malfunctioning side. They often share a single socket, but may be separate in some configurations. Look for a burnt-out filament. Replace any faulty bulbs with the correct wattage. Make sure you're using the correct type of bulb specified in your owner's manual or a parts catalog.
2. Fuses:
* Check the fuses: Consult your owner's manual to locate the fuse box and identify the fuses related to the brake lights and taillights. A blown fuse will interrupt power to the entire circuit. Replace any blown fuses with the correct amperage. Don't just replace a blown fuse without investigating *why* it blew – a short circuit could blow another fuse immediately.
3. Wiring:
* Inspect the wiring: Carefully examine the wiring harness leading to the taillight assembly on the malfunctioning side. Look for any broken, frayed, or corroded wires. Pay close attention to the connections at the bulb sockets and the harness connectors. A visual inspection might reveal a problem, but sometimes a multimeter is needed to test continuity.
* Ground: A poor ground connection can prevent the brake lights from working. Locate the ground wire for the taillight assembly and make sure it's clean and making good contact with the car's chassis. Clean any corrosion with a wire brush and reconnect securely.
4. Brake Light Switch:
* Check the brake light switch: This switch is usually located on the brake pedal assembly. It's activated when you press the brake pedal, completing the circuit to the brake lights. You might be able to test it with a multimeter (checking continuity when the brake pedal is pressed) or have a helper check the brake lights while you manually activate the switch. A faulty switch needs to be replaced.
5. Wiring Harness Connector:
* Inspect the connectors: There might be corroded connectors on the wiring harness within the car or near the tail lights. Clean and re-seat these connectors.
6. Tail Light Assembly:
* Check the sockets: The problem may be with the sockets inside the tail light assembly. A corroded socket may prevent the bulb from making a good connection. Clean the sockets and test carefully.
7. Multi-meter:
* Use a multimeter: If you're comfortable with basic electrical testing, a multimeter is invaluable for checking voltage at various points in the circuit, checking continuity of wires, and verifying ground connections. This will help pinpoint exactly where the fault lies. (Consult online resources for how to test automotive circuits safely).
If you're not comfortable working with automotive electrical systems, it's best to take your Trans Am to a qualified mechanic. Improper repairs can lead to further damage or even create safety hazards. Remember safety first – disconnect the battery negative terminal before working on the electrical system.
