Ignition Coil - Single

This procedure covers removal and replacement of the ignition coil on a 1966 Chevrolet Corvette with 327ci V8 engine, including disconnecting battery power, removing old coil, and installing new coil with proper electrical connections.

Warnings

Tools required

Parts

• Ignition coil × 1 — Use OEM specification or aftermarket equivalent rated for points ignition system

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool if recently operated
3. Open hood and prop securely
4. Disconnect negative battery cable at battery terminal

Procedure

1. 1

   Locate ignition coil
   The ignition coil is mounted on a bracket on the intake manifold near the front of the engine, with the high-tension wire routing back to the rear-mounted distributor. It is a cylindrical component approximately 4-5 inches tall with a high-tension wire leading to the center of the distributor cap and two primary wire terminals on top. It is a cylindrical component approximately 4-5 inches tall with a high-tension wire leading to the center of the distributor cap and two primary wire terminals on top.
2. 2

   Disconnect high-tension wire
   Grasp the rubber boot at the top center of the coil and pull firmly straight up to disconnect the high-tension wire that runs to the distributor cap. Do not pull on the wire itself - always pull on the boot to avoid damaging the wire core.
3. 3

   Disconnect primary wiring
   Remove the two primary wires from the terminals on top of the coil. These are typically marked with a '+' (positive) and '-' (negative or distributor) terminal. On 1966 Corvettes, these connections are usually push-on terminals that can be pulled straight off, or small nuts that require a 3/8" wrench. Note the position of each wire for correct reinstallation - the wire from the ignition switch (through the resistance wire) connects to the '+' terminal, and the wire from the distributor points connects to the '-' terminal.
4. 4

   Remove coil mounting hardware
   Remove the coil mounting bracket bolt or clamp that secures the coil to its mounting location. Most 1966 Corvette 327 installations use a single 7/16" bolt through a metal clamp bracket that wraps around the coil body. Remove this bolt completely and slide the clamp bracket off the coil.
5. 5

   Remove old coil
   Lift the ignition coil straight up and out of its mounting location. Inspect the mounting area for corrosion or debris.
6. 6

   Prepare mounting surface
   Clean the coil mounting surface with a wire brush if corrosion is present. Wipe clean with a rag. If the coil was mounted with rubber isolators or spacers, inspect them for cracking or deterioration and replace if necessary.
7. 7

   Inspect new coil
   Verify the replacement coil matches the original in physical dimensions and terminal configuration. Check that the primary terminals are clearly marked with polarity indicators. Confirm the coil is rated for points-type ignition systems (not CDI or electronic ignition unless the vehicle has been converted).
8. 8

   Install new coil
   Position the new ignition coil in the mounting bracket or location, ensuring any rubber isolators are properly seated. Orient the coil so the primary terminals are accessible and positioned similarly to the original installation for proper wire routing.
9. 9

   Secure coil mounting hardware
   Install the mounting clamp bracket around the coil body and thread the mounting bolt through the bracket. Tighten the bolt securely by hand plus approximately 1/4 turn with the wrench - sufficient to hold the coil firmly without crushing it. The coil should not rotate or move when pulled gently.
10. 10

    Connect primary wiring
    Connect the two primary wires to the correct terminals on the new coil. The wire from the ignition switch/resistance wire connects to the '+' (positive) terminal. The wire running to the distributor connects to the '-' (negative/distributor) terminal. Refer to the original wiring and the position you noted during removal rather than relying on wire color. Push terminal connectors firmly onto the posts until fully seated, or thread nuts finger-tight plus 1/4 turn if equipped with threaded studs.
11. 11

    Connect high-tension wire
    Push the high-tension wire boot firmly onto the center tower of the new coil until it seats completely with a firm stop. Ensure the boot is fully engaged to prevent arcing or misfires. Ensure the boot is fully engaged to prevent arcing or misfires.

Reassembly

1. Reconnect negative battery cable at battery terminal
2. Verify all electrical connections are secure and wires are routed away from hot exhaust components and moving parts

Verification

• Turn ignition key to 'ON' position (do not start) and verify no sparking or arcing at coil connections
• Start engine and listen for smooth idle with no misfiring
• Rev engine gently to 2000 RPM and verify smooth operation without hesitation
• Inspect coil and all connections while engine runs for signs of arcing, smoke, or unusual heat
• Turn off engine and check that mounting hardware remains tight

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