Before diagnosing starter problems, ensure the battery is fully charged. If the starter motor does not turn when the switch is operated, check that the shift lever is in Neutral or Park for automatic transmissions, or that the clutch pedal is depressed for manual transmissions. Verify that the battery is charged and that all cables at the battery and starter solenoid terminals are clean and secure. If the starter motor spins but the engine does not crank, the overrunning clutch in the starter motor is slipping, necessitating replacement of the starter motor. If the starter motor does not operate at all but the solenoid clicks when the switch is actuated, the issue may be with the battery, main solenoid contacts, starter motor, or a seized engine. If the solenoid plunger is not audible when the switch is actuated, the battery may be bad, the fusible link could be burned, the starter relay might be defective, or the starter solenoid itself could be faulty. To check the solenoid, connect a jumper lead between the battery positive and the ignition switch terminal on the solenoid; if the starter motor operates, the solenoid is functioning, indicating a problem with the ignition switch, Neutral start switch, or wiring. If the starter motor still does not operate, remove the starter/solenoid assembly for disassembly, testing, and repair. If the starter motor cranks the engine slowly, ensure the battery is charged and all terminal connections are tight; a partially seized engine or incorrect oil viscosity can also cause slow cranking. Run the engine until it reaches normal operating temperature, then disconnect the coil wire from the distributor cap and ground it on the engine, or detach the primary electrical connectors from the ignition coils on models with distributor-less ignition systems. Connect a voltmeter positive lead to the battery positive post and the negative lead to the negative post. Crank the engine and take voltmeter readings as soon as a steady figure is indicated, avoiding more than 16 seconds of starter motor operation at a time. A reading of nine volts or more with normal cranking speed is acceptable; if the reading is nine volts or more but cranking speed is slow, the motor is faulty. If the reading is less than nine volts and cranking speed is slow, the solenoid contacts may be burned, the starter motor could be bad, the battery might be discharged, or there may be a bad connection.
Posted by ToyotaPartsDeal Specialist