Finding the correct wiring diagram for your 1966 Chevelle's big block ignition system can be tricky. This guide will help you navigate the specifics, understand the components, and troubleshoot any potential issues. While a PDF diagram isn't directly provided (due to copyright restrictions on original manufacturer documents), this detailed explanation and visual descriptions will be just as effective. Remember to always disconnect the negative battery terminal before working on your vehicle's electrical system.
Understanding the 1966 Chevelle Big Block Ignition System
The ignition system in a 1966 Chevelle big block is a points-based system, meaning it uses breaker points to trigger the coil. This is different from later electronic ignition systems. This system relies on several key components:
- Ignition Coil: This is the transformer that boosts the 12-volt battery current to the high voltage needed to fire the spark plugs.
- Breaker Points (Distributor Points): These mechanical contacts in the distributor open and close, creating the interruption of current necessary to generate the high voltage in the coil.
- Distributor: This houses the breaker points, the rotor, and the centrifugal and vacuum advance mechanisms. It's responsible for distributing the high voltage to the correct spark plug at the right time.
- Ballast Resistor (if equipped): Some models utilize a ballast resistor to limit the current flow to the coil during cranking and running to extend coil life. This resistor is often inline with the ignition coil's primary circuit.
- Ignition Switch: This switch controls the power flow to the ignition system.
- Spark Plugs: These deliver the high voltage spark to ignite the air-fuel mixture in the cylinders.
What are the common wiring components related to the 1966 Chevelle Big Block Ignition Coil?
The wiring itself will be relatively simple but crucial for correct function. You'll find wires connecting:
- Battery (+) to the Ignition Switch: Provides power to the system.
- Ignition Switch to the Coil (+) Terminal: Sends power to the coil, possibly through a ballast resistor.
- Coil (-) Terminal to the Distributor Points: This completes the primary circuit when the points close.
- Distributor to the Coil (+) Terminal (Secondary): High-voltage wire leads to the distributor cap.
- Distributor Cap to the Spark Plugs: Distributes the high voltage to each cylinder's spark plug.
How do I identify the correct wiring for the 1966 Chevelle Big Block ignition coil?
Unfortunately, a generalized diagram won't suffice for all 1966 Chevelle big blocks. Variations exist based on specific engine options and any aftermarket modifications. Your best bet is to:
- Consult your original owner's manual: If you have access to one for your specific model year and engine, it should contain a wiring diagram.
- Find a model-specific shop manual: These manuals, such as those from Chilton or Haynes, are detailed resources, often including clear wiring diagrams.
- Examine the existing wiring harness: Carefully tracing existing wiring can often help you determine the correct connections. Take pictures as you go!
Remember to check for any color-coded wires and their connections. Consistency and attention to detail are crucial.
What if my 1966 Chevelle big block ignition system is not working?
Several things can cause ignition system problems. This includes:
- Faulty coil: Testing the coil with a multimeter is essential for diagnosis.
- Worn or dirty points: These require cleaning or replacement.
- Bad condenser: This component works with the points and needs to be checked.
- Damaged distributor cap or rotor: These can cause misfires or no spark.
- Wiring issues: Check for broken or corroded wires and connections.
Troubleshooting a non-functioning ignition system requires methodical testing of each component. This requires testing for continuity, resistance, and voltage.
Can I upgrade my 1966 Chevelle Big Block to an electronic ignition system?
Yes! Upgrading to an electronic ignition system is a common modification, as it offers increased reliability and performance compared to the original points-based system. Numerous kits are available that are designed to replace the points, condenser and associated circuitry, providing a more reliable and higher performance ignition system.
This detailed overview should significantly help in understanding the wiring of your 1966 Chevelle Big Block's ignition system. Remember to consult a professional mechanic if you are not comfortable working with your car's electrical system. Always prioritize safety first!
