If the engine won’t start and the battery is good, what should you check next?

When an engine won’t start and the battery is confirmed to be good, the next logical step is to investigate both the ignition system and the fuel delivery system. The ignition system is crucial for generating the spark needed to ignite the air-fuel mixture within the cylinders. If there's a fault in components such as the ignition coil, spark plugs, or ignition timing, the engine may fail to start despite having a functional battery.

Simultaneously, the fuel delivery system plays an essential role as well. It ensures that the right amount of fuel is delivered to the engine. Issues with the fuel pump, fuel filter, or fuel injectors can prevent the engine from receiving fuel, which would also inhibit starting.

Both systems must be functioning correctly for the engine to start. Unlike the ignition and fuel systems, the air conditioning system, brake system, and transmission fluid level are not directly related to engine starting issues. Thus, focusing on the ignition and fuel systems is the most appropriate next step in diagnosing a no-start condition.