1. Understanding the Circuit:
* Reverse Light Switch: The Turbo 400 transmission has a reverse light switch. This switch is activated only when the transmission is in reverse. This switch provides the power to your reverse lights.
* Wiring Harness: The switch is connected to the car's wiring harness. This harness usually runs from the transmission to a fuse box or other junction point, and then to the lights themselves.
* Reverse Light Wires: These are typically a pair of wires (one for each reverse light). They are usually a light gauge wire (16-18 AWG). They may be a different color from the rest of the car's wiring harness.
2. Locating Components:
* Transmission Reverse Light Switch: This is usually located on the side of the transmission, near where the transmission attaches to the engine. It's often a small, easily accessible switch.
* Wiring Harness Connection: Find the connector that plugs into the reverse light switch on the transmission.
* Reverse Light Wires at the Switch: Identify the two wires coming from the reverse light switch. They may be a different color, and often have a slightly smaller gauge than other wiring. A wiring diagram for your specific year and model is invaluable here. A shop manual is highly recommended.
* Reverse Lights: Locate the reverse lights themselves in the rear of the vehicle.
3. Testing and Tracing:
* Check the Switch: Before you start, make sure your reverse light switch is working. With the transmission in reverse, you should be able to measure continuity across the two terminals using a multimeter. If there is no continuity, the switch needs to be replaced.
* Trace the Wires: Carefully trace the wires from the switch back to the lights, paying attention to the wire colors and where they connect.
4. Wiring (Only if you know what you're doing - Consult a wiring diagram!):
This step should only be attempted if you have experience with automotive electrical systems and are comfortable working with 12V DC electricity. Incorrect wiring can lead to shorts, blown fuses, or even damage to your car's electrical system.
1. Disconnect the Battery's Negative Terminal: This is crucial to prevent accidental shorts and electrical shocks.
2. Identify the Correct Wires: Consult your wiring diagram to positively identify the reverse light wires at both the switch and the lights.
3. Check for Existing Wiring: If the wiring is already partially there but doesn't work, troubleshoot why it's not working before replacing any wires. A bad connection, broken wire, or blown fuse are all possibilities.
4. Repair or Replace: If the existing wiring is damaged, replace it with appropriately-sized wire (16-18 AWG).
5. Connect the Wires: Connect the wires from the reverse light switch to the reverse light bulbs, ensuring a secure connection. Crimp connectors are recommended over twisting.
6. Protect the Wiring: Properly secure and protect all wiring, preventing it from rubbing against moving parts or getting damaged.
7. Reconnect the Battery's Negative Terminal: Once everything is connected, check your work thoroughly before reconnecting the battery.
8. Test the Reverse Lights: Shift the transmission into reverse and check that the reverse lights turn on correctly.
Caution: Incorrect wiring can cause serious damage. If you are uncomfortable working with automotive electrical systems, consult a qualified mechanic. A wiring diagram specific to your 1973 Firebird is highly recommended, and a shop manual will have exploded diagrams showing how to access the components.
Where to find a wiring diagram:
* Online forums: Search for "1973 Firebird wiring diagram" on forums dedicated to classic cars.
* Repair manuals: A Haynes or Chilton repair manual for your car will contain detailed wiring diagrams.
* Online parts retailers: Some online parts retailers might offer free wiring diagrams as a service.
Remember safety first! If you're unsure about any step, seek professional help.
