1. Gather Necessary Information:
* Identify your ignition system: Is it HEI (High Energy Ignition), points, or something else? The 6AL's connection will vary depending on this. '84 Chevy trucks *usually* had HEI.
* Obtain a wiring diagram: Find a wiring diagram specific to your 1984 Chevy truck's year, engine, and options (e.g., AC, power steering). This is crucial for understanding your vehicle's existing wiring. Online resources like wiring diagrams.com might be helpful, but accuracy is critical. A factory service manual is the best source.
* MSD 6AL instructions: Carefully review the instructions provided with your MSD 6AL ignition box. This is your primary source for accurate wiring information for the box itself.
2. Key Connections (General):
* Power (Battery): The MSD 6AL requires a 12V power source. This should be a switched 12V source (only on when the ignition is on) to prevent battery drain. Use a properly sized fuse (typically 10-15 amps) in-line with this power wire, as close to the battery as possible.
* Ground: Connect the ground wire from the MSD 6AL to a clean, solid ground point on the engine block or chassis. A poor ground can cause all sorts of ignition problems.
* Coil Wire: This is the crucial connection. The MSD 6AL replaces your truck's stock ignition module's function. The coil wire from the distributor connects to the MSD 6AL's coil output terminal.
* Distributor Pickup (Trigger): This is how the MSD 6AL "knows" when to fire the coil. If you have an HEI distributor, you will typically connect this to the "crankshaft sensor" (or "trigger") input on the 6AL. The exact location and wiring will depend on your distributor. This connection is critical and often the most challenging to get right.
* Tachometer Output (Optional): If you want to connect a tachometer, the MSD 6AL usually has a tach output terminal.
3. Potential HEI Specific Connections:
With an HEI system, the MSD 6AL will essentially replace the internal module within the distributor. The process is often to bypass the stock HEI module and use the 6AL's trigger input to control the ignition timing. However, this often requires careful adaptation and wiring knowledge. You may need to:
* Disconnect the internal HEI module: This usually involves disconnecting the wires from the module.
* Connect the trigger wire: Connect the trigger wire from the distributor's pickup coil to the correct input on the MSD 6AL.
* Verify correct timing: After installation, verifying the ignition timing is crucial.
4. Safety Precautions:
* Disconnect the battery negative terminal before starting any wiring work.
* Use appropriately sized wire and fuses.
* Double-check all connections before reconnecting the battery.
* If unsure, consult a professional. Improper installation can cause significant damage to your vehicle's electrical system.
In short: Successfully wiring an MSD 6AL to your 1984 Chevy truck requires more than just a general guide. The nuances of your specific vehicle's electrical system are paramount. A wiring diagram and possibly professional assistance are strongly recommended. Improper wiring can lead to engine damage or fire.
