Converting an antique vehicle from the old 6 volt system to a modern 12 volt allows the use of more accessories and easier repairs. The ignition system is no different and having more voltage available gives the system more energy. This energy translates into a more efficient engine with more power that uses less fuel. After a 12 volt conversion has been done on an older vehicle, the ignition must be upgraded also. Converting the ignition to handle 12 volts is a very simple job that can be done in just a few minutes.
Shift the vehicle into park or neutral. Disconnect the battery negative (-) terminal. Inspect the existing ignition system wiring and other components for wear or damage. Replace any defective parts as required.
Locate the vehicle ignition coil. Remove the original 6 volt coil following the manufacturer's instructions. Install a universal 12 volt coil in the original coil's location on the vehicle. It may be necessary to replace the existing coil bracket in order to fit the new coil. Most universal coils come complete with mounting brackets as part of the kit. Install the new bracket following the coil manufacturer's instructions. Do not connect the wire from the ignition switch to the coil at this time.
Locate a suitable mounting point near the coil for the single winding ballast resistor. The single ballast resistor is identified by having two prongs for electrical connection. Typically the ballast resistor is best mounted on the firewall of the vehicle. Use care when selecting a mounting location as the ballast resistor becomes hot during normal operation. Connect the wire from the ignition switch to one side of the ballast resistor. Cut a piece of 12 gauge wire to fit from the other terminal of the ballast resistor to the coil. Install spade or loop connectors on the wire ends as required. Attach one end of the wire to the ballast resistor and attach the other end to the ignition coil.
Locate the distributor and remove the distributor cap and rotor by following the vehicle manufacturer's instructions. Locate the ignition condenser inside the distributor and remove it from the vehicle. Install a 12 volt condenser in the same location as the original unit. It is not necessary to change the ignition points or any other component as they are not voltage sensitive. Replace the distributor cap and rotor.
Inspect the ignition system and ensure all components are solidly connected and away from any moving parts of the vehicle. Connect the battery negative (-) cable. Start the vehicle and check for normal operation. If the vehicle fails to start, switch the wires around at the coil connections.
