1. Acquire the Necessary Parts:
* Third brake light assembly: This needs to be compatible with your car's rear window shape and size. You can find these at auto parts stores, online retailers, or even salvage yards.
* Wiring harness: This will connect the new light to your car's existing brake light circuit. You might be able to find a pre-made harness specific to your car, or you may need to create your own using appropriate gauge wire.
* Mounting hardware: This could include bolts, screws, nuts, and possibly adhesive or sealant.
* Soldering iron and solder (or crimp connectors): For safely connecting wires.
* Electrical tape: To insulate connections.
* Wire strippers and cutters: For preparing the wires.
* Test light or multimeter: To check the brake light circuit.
2. Plan the Installation:
* Location: Determine the best location for the third brake light. Ideally, it should be centrally located and highly visible. This often involves mounting it on the rear window shelf or a designated area on the rear deck.
* Wiring route: Plan the path for the wiring harness from the brake light assembly to the car's existing brake light wiring. Try to keep it hidden and protected from damage. You may need to remove interior trim pieces to access the wiring.
* Power source: The third brake light needs to be connected to the brake light circuit. This usually involves tapping into the wiring harness for the existing brake lights.
3. Installation Steps:
* Prepare the mounting location: Clean the area where the third brake light will be mounted. You may need to drill holes or otherwise modify the area to accommodate the mounting hardware.
* Mount the brake light: Securely attach the brake light assembly to the chosen location.
* Wire the brake light: This is the most critical step and requires careful attention to detail.
* Locate the brake light wiring: Find the wires that power your existing brake lights. Consult your car's wiring diagram.
* Connect the new wiring: Carefully connect the wires from the new brake light to the existing brake light circuit. Make sure to use the correct polarity (positive and negative). Solder and heat-shrink tubing are recommended for reliable connections. Crimp connectors are acceptable if done properly.
* Test the connection: Before completely sealing things up, test the new brake light to ensure it works correctly. Turn on your brake lights and check that the new third brake light illuminates.
* Route and secure the wiring: Carefully tuck the wiring away, securing it with zip ties or other fasteners to prevent it from being damaged or interfering with other components.
* Reinstall trim pieces: Reassemble any interior trim pieces that you removed.
* Final test: Conduct a final test to ensure the third brake light functions correctly and the installation is secure.
Important Safety Considerations:
* Disconnect the battery negative terminal before starting any electrical work to prevent short circuits or shocks.
* Use appropriate gauge wire: Too thin of wire can overheat and cause a fire.
* Secure all wiring connections: Loose connections can cause intermittent operation or electrical shorts.
* Protect wiring from heat and abrasion: Route wires away from moving parts and hot surfaces.
If you're not comfortable with electrical work, it's best to have a qualified mechanic install the third brake light. Improper wiring can lead to electrical problems or even a fire. Remember, the instructions above are general; you must consult your vehicle's specific wiring diagram for precise instructions.
