Q: How to diagnose starter issues?A: Before diagnosing starter issues, ensure the battery is fully charged. If the starter fails to operate when the switch is turned to Start, confirm the shift lever is in Neutral or Park (for automatic transmissions) and check battery charge and cable connections. If the starter spins but the engine doesn't crank, the starter motor's overrunning clutch may be slipping, necessitating starter motor replacement. When the starter doesn't operate but the solenoid clicks, examine the battery, starter relay (if applicable), main solenoid contacts, starter motor, or consider the possibility of a seized engine. If the solenoid plunger isn't heard when the switch is activated, inspect the battery, look for a burned fusible link (indicating an open circuit), or consider a defective solenoid. To test the solenoid, connect a jumper lead between the battery (+) and the ignition switch wire terminal on the solenoid; if the starter operates, the solenoid is functional, and the issue lies with the ignition switch, neutral start switch, or wiring. If the starter still doesn't function, remove the starter/solenoid assembly for disassembly, testing, and repair. If the starter cranks the engine slowly, check the battery charge, ensure tight terminal connections, and consider engine problems such as partial seizing or incorrect oil viscosity. Conduct a voltage test during cranking, aiming for a reading of 9 volts or more at normal cranking speed; readings below 9 volts with slow cranking may indicate solenoid contact issues, a faulty starter motor, discharged battery, or poor connections.