1966 Chevelle Big Block Ignition Coil Wiring: A Deep Dive
Finding the correct wiring diagram for your 1966 Chevelle's big block ignition system can be tricky, especially when dealing with variations across different models and production runs. This guide aims to clarify the intricacies of the system, providing a comprehensive understanding of the ignition coil wiring and addressing common questions. While a precise PDF diagram is unavailable for general distribution due to copyright restrictions and the variations in specific models, this detailed explanation will provide the information needed to diagnose and repair your system. We will examine the components involved, their functions, and common troubleshooting steps.
Understanding the 1966 Chevelle Big Block Ignition System
The 1966 Chevelle big block ignition system, while seemingly simple, relies on a precise interaction of components. The primary components include:
- Ignition Coil: This is the transformer that boosts the low-voltage current from the ignition system to the high voltage required to fire the spark plugs.
- Distributor: This houses the points (in most cases), the condenser, and the rotor, distributing the high voltage to the correct spark plug at the right time.
- Ignition Switch: This is the on/off switch for the entire ignition system.
- Ballast Resistor (if equipped): This resistor protects the points from excessive current during cranking. Some models used a ballast resistor, others didn't. This is a key area to understand for accurate wiring.
- Wiring Harness: This connects all components and carries the power and signals.
Common Wiring Configurations (Variations Exist)
The wiring will vary slightly based on options such as the presence of a ballast resistor and the specific ignition system used. However, the core principle remains the same. Here's a generalized overview:
- Positive (+) Battery Cable: This provides the primary power source to the ignition system, typically connecting directly to the starter solenoid and then to the ignition switch.
- Ignition Switch Output: This feeds power to the coil. If a ballast resistor is used, this will go through the resistor during running.
- Coil (+) Terminal: Receives power from the ignition switch (possibly through a ballast resistor).
- Coil (-) Terminal: Connects to the distributor. Specifically, this terminal would typically connect to the distributor points.
- Distributor Points: These open and close, interrupting the current to the coil, creating the high-voltage spark.
- Distributor Condenser: This helps suppress the arcing across the points, extending their lifespan.
- Distributor Rotor: This distributes the high voltage to the spark plug wires.
- Spark Plug Wires: Carry the high-voltage spark to the spark plugs.
H2: Does my 1966 Chevelle Big Block use a ballast resistor?
The presence of a ballast resistor is crucial in determining the correct wiring. Not all 1966 Chevelles used them. The resistor is typically in-line with the positive wire to the coil. Its function is to reduce the current to the points during normal operation, protecting them from excessive wear. However, during cranking, it's usually bypassed to allow full power to jump start the engine. To ascertain if yours has a ballast resistor, visually inspect the wiring harness near the coil and distributor; a small cylindrical resistor is a clear indicator. Consulting your owner's manual (if available) or a reputable Chevelle parts catalog specific to your model and engine options is recommended.
H2: How do I trace the wiring on my 1966 Chevelle's ignition system?
Carefully tracing the wires is essential for accurate diagnosis. Start at the ignition switch, tracing the wires to the coil and distributor. Use a wiring diagram (if you can find a model-specific one) to correlate the colors with their functions. A multimeter can help verify the continuity and voltage of each wire. Begin with the battery’s positive terminal and trace to the coil and distributor, methodically verifying connections. Always disconnect the battery’s negative terminal before starting any diagnostic procedure.
H2: What are the common problems in the 1966 Chevelle big block ignition system?
Common issues include faulty points, a bad condenser, a failing ignition coil, worn distributor cap or rotor, broken or corroded wires, and a failing ignition switch. Addressing each component systematically with the guidance of a multimeter is recommended.
Disclaimer: This information is for educational purposes only. Always consult a qualified mechanic for any vehicle repair or maintenance work. Incorrect wiring can lead to damage to your vehicle’s electrical system. While a generic explanation is provided here, specific wiring configurations might vary slightly between different models and production years. Referencing a wiring diagram specific to your vehicle is vital for accurate identification and repair.
