The Ultimate DIY: Mastering How to Wire Ignition Coil with Points

The rumble of a classic engine is a symphony of mechanical harmony, and at the heart of that symphony lies the ignition system. For many classic cars, this system relies on points and a coil to generate the spark that ignites the fuel-air mixture. Understanding how to wire an ignition coil with points is crucial for keeping your classic running smoothly. This guide will walk you through the process, step-by-step, ensuring you can confidently tackle this essential task.

The Importance of the Ignition Coil and Points

The ignition coil is the heart of the ignition system, transforming low-voltage battery power into the high-voltage spark needed to ignite the fuel. The points, or breaker points, act as a mechanical switch, interrupting the flow of current to the coil, creating the magnetic field collapse that generates the spark. Here’s a breakdown of their roles:

• Ignition Coil: The coil consists of two windings: a primary winding and a secondary winding. When the primary winding is energized by the battery, a magnetic field builds up. When the points open, this magnetic field collapses rapidly, inducing a high-voltage current in the secondary winding. This high-voltage current is then directed to the spark plugs.

• Points: The points are a pair of contacts that open and close, interrupting the flow of current to the primary winding of the coil. The timing of this opening and closing is crucial for proper engine operation. The points are typically mounted on a camshaft, opening and closing in sync with the engine’s rotation.

Tools and Materials Needed

Before you begin, gather the necessary tools and materials:

• Ignition Coil: Ensure it’s compatible with your car’s model and year.
• Points: These should be the correct type for your car’s distributor.
• Wires: Use high-quality ignition wires specifically designed for high-voltage applications.
• Screwdriver: A Phillips head screwdriver is typically needed for securing the coil and points.
• Wrench: A wrench may be required for loosening or tightening mounting bolts.
• Multimeter: This is essential for testing the coil and points.
• Wire strippers: For stripping the insulation off the wires.
• Electrical tape: For securing connections and preventing shorts.
• Service Manual: Consult your car’s service manual for specific wiring diagrams and instructions.

Step-by-Step Wiring Guide

Now, let’s dive into the wiring process:

1. Disconnect the Battery: Safety first! Before working on any electrical components, disconnect the negative terminal of the battery to prevent accidental shocks.

2. Locate the Ignition Coil: The ignition coil is typically mounted near the distributor on older cars. Identify the coil and its terminals. Most coils have three terminals:

• Positive Terminal (POS): This terminal receives the battery power.
• Negative Terminal (NEG): This terminal is connected to the distributor.
• Secondary Terminal (SEC): This terminal carries the high-voltage current to the distributor.

3. Locate the Points: The points are usually housed within the distributor. Identify the two terminals of the points:

• Positive Terminal: This terminal connects to the coil’s negative terminal.
• Negative Terminal: This terminal connects to the distributor’s internal circuitry.

4. Connect the Battery Power: Connect a wire from the battery’s positive terminal to the coil’s positive terminal. Secure the connection with electrical tape.

5. Connect the Coil to the Points: Connect a wire from the coil’s negative terminal to the points’ positive terminal. Secure this connection with electrical tape.

6. Connect the Points to the Distributor: Connect a wire from the points’ negative terminal to the distributor’s internal circuitry. This wire is often a single wire that runs from the points to a terminal on the distributor cap. Secure the connection with electrical tape.

7. Connect the Coil to the Distributor: Connect a wire from the coil’s secondary terminal to the distributor cap. This wire is usually a high-voltage wire with a boot that fits over the distributor cap terminal. Secure the connection with electrical tape.

8. Reconnect the Battery: Once all connections are secure, reconnect the battery’s negative terminal.

Testing the Ignition System

After wiring the ignition coil and points, it’s essential to test the system to ensure it’s functioning correctly. Use a multimeter to:

• Test the coil: Check the continuity of the primary winding by connecting the multimeter’s probes to the coil’s positive and negative terminals. The multimeter should read a low resistance. Then, check the continuity of the secondary winding by connecting the probes to the coil’s secondary terminal and ground. The multimeter should read a higher resistance.

• Test the points: With the ignition key turned on, check the continuity of the points. The multimeter should read zero resistance when the points are closed and infinite resistance when they are open.

Maintaining your Ignition System

Keeping your ignition system in tip-top shape is crucial for optimal engine performance. Here are some key maintenance tips:

• Regular Point Inspection: Inspect the points for wear and tear. Replace them when necessary, as worn points can cause misfires and ignition problems.

• Point Gap Adjustment: The gap between the points is critical for proper timing. Use a feeler gauge to adjust the gap according to your car’s specifications.

• Coil Testing: Periodically test the coil for proper operation. A faulty coil can lead to a weak spark and poor engine performance.

• Distributor Cap and Rotor: Inspect the distributor cap and rotor for cracks, wear, and corrosion. Replace them if necessary.

• Spark Plugs: Replace spark plugs according to your car’s maintenance schedule. Worn spark plugs can cause misfires and reduce engine efficiency.

Optimizing Performance: Beyond the Basics

While the basic wiring is essential, there are additional steps you can take to enhance your classic’s performance:

• Upgrade to Electronic Ignition: Consider upgrading to an electronic ignition system, which eliminates the mechanical points and provides more reliable and accurate timing.

• High-Performance Coil: Install a high-performance ignition coil for increased spark energy and improved combustion.

• High-Performance Spark Plugs: Use high-performance spark plugs designed for your engine’s specific requirements.

• Proper Timing: Ensure your engine’s ignition timing is set correctly for optimal performance and fuel efficiency.

The Final Tune-Up: Ensuring a Smooth Ride

By understanding the fundamentals of wiring an ignition coil with points and implementing the maintenance tips outlined, you can keep your classic engine running smoothly and reliably. Remember, a well-maintained ignition system is the foundation for a satisfying driving experience.

Questions We Hear a Lot

Q: How often should I replace my points?

A: Points typically need to be replaced every 10,000 to 15,000 miles, or sooner if they show signs of wear.

Q: What are the symptoms of a faulty ignition coil?

A: A faulty ignition coil can cause misfires, rough idling, difficulty starting, and a loss of power.

Q: How do I know if my points are properly adjusted?

A: The correct point gap is typically specified in your car’s service manual. Use a feeler gauge to measure the gap between the points and adjust them accordingly.

Q: Can I use a standard spark plug in my classic car?

A: It’s best to use spark plugs specifically designed for your engine’s requirements. Consult your car’s service manual for recommendations.

Q: What’s the difference between a standard ignition coil and a high-performance coil?

A: A high-performance coil produces a stronger spark, which can improve combustion and increase horsepower. However, they may require a higher voltage than a standard coil.