Check battery voltage and connections
Turn the key to START and listen for a click
Inspect starter wiring and ground connections
Test for voltage at the starter solenoid terminal
Perform a voltage drop test on the positive cable
Perform a voltage drop test on the ground cable
Bypass the starter relay if applicable
Bench test the starter with jumper cables
Check for free rotation of the starter gear
Inspect the starter drive and flywheel teeth
Replace the starter if it fails bench or circuit tests