Ignition System Problems:
* Ignition Coil: The coil is the heart of the system. It could be:
* Faulty: Internally shorted, cracked insulation, or simply worn out.
* Not receiving power: Check the power wire connection and the coil's +12V supply.
* Ignition Switch: The switch itself could be faulty, preventing power from reaching the coil or other components.
* Distributor: A multitude of problems can plague the distributor:
* Rotor: Cracked, burnt, or improperly seated.
* Cap: Cracked, burnt, or with corroded contact points. High resistance in the cap can prevent a strong spark.
* Points (if equipped): Worn, pitted, or improperly gapped points are a common cause of no spark in points-ignition systems. They need to be adjusted correctly. If you have electronic ignition, skip this.
* Distributor shaft: Worn or damaged, causing poor rotor contact with the cap.
* Internal wiring: Broken or corroded wiring within the distributor.
* Ignition Wires (Spark Plug Wires): Cracked, frayed, or improperly connected wires will prevent the spark from reaching the plugs. Check for shorts or breaks. Look closely at the boots that connect to the distributor cap and spark plugs; they can become brittle over time.
* Spark Plugs: Fouled, damaged, or incorrectly gapped spark plugs won't fire. Try new ones.
* Ignition Control Module (if equipped): Some 1965 Corvettes might have had an early form of electronic ignition. A faulty module would prevent spark.
Power Supply Problems:
* Battery: A weak or dead battery won't provide enough power to the ignition system. Check the voltage.
* Battery Cables: Corroded or loose battery cables can restrict current flow. Clean the terminals and ensure tight connections.
* Fuses: A blown fuse in the ignition circuit will kill the spark.
* Wiring: Broken or corroded wires anywhere in the ignition circuit can interrupt the flow of electricity. Check all connections, particularly those under the dash and near the engine.
Troubleshooting Steps:
1. Check the basics: Battery voltage, fuse status, and obvious wiring issues.
2. Test the coil: Use a multimeter to check for continuity and voltage at the coil terminals.
3. Inspect the distributor: Carefully examine the cap, rotor, points (if applicable), and internal wiring for damage.
4. Check the spark plug wires: Visually inspect them for damage and test for continuity with a multimeter.
5. Test the spark plugs: Check the gap and condition of the spark plugs.
6. Check the ignition switch: Verify that power is reaching the coil when the ignition key is turned.
7. Try a known-good component: If you suspect a particular component (coil, distributor, etc.), try swapping it with a known-good one from a similar vehicle to isolate the problem.
Remember safety first! Disconnect the negative battery terminal before working on the ignition system. A Haynes or Chilton manual for your specific year and model Corvette will be invaluable in providing detailed wiring diagrams and troubleshooting information. If you're not comfortable working on the electrical system, seek the help of a qualified mechanic.
