When troubleshooting a starting circuit malfunction, check
Battery Cable clamps, cables, battery condition, starter solenoid wiring, connections, and mounting bolts. Also, ensure shift lever is in PARK or NEUTRAL. If starter doesn't operate when ignition is turned to START, check for battery voltage to solenoid and test starting system circuit. If starter turns over slowly, check cranking voltage and current drawn from battery. If values are incorrect, replace starter. If starter receives voltage but doesn't activate, remove and check starter/solenoid assembly on bench, ensuring engine isn't seized. If solenoid plunger extends and rotates pinion drive, assembly is working properly.