What component measurement is critical for testing ignition systems?

Resistance is a critical measurement for testing ignition systems because it helps determine the integrity and functionality of various components like ignition coils, spark plugs, and wiring. In an ignition system, if the resistance is outside the manufacturer’s specified range, it can indicate problems such as wear, internal shorts, or failures in the coil or other electrical components. High resistance may signal poor connections, while low resistance could indicate a short in the circuit. Proper resistance values ensure that the ignition system can produce the necessary voltage to create a spark efficiently, which is essential for engine performance and efficiency.

Voltage, while also important, primarily assesses the system's ability to deliver power rather than the condition of the components. Current measurements mainly help determine the flow of electricity and can indicate the load on the system. Frequency is typically not a relevant measurement for standard ignition system testing. Therefore, focusing on resistance provides the technician with essential information about the health of the ignition components and their operational readiness.