Do not assume immediately that the trouble is the starter when a malfunction occurs in the starting circuit. Inspect the condition of the battery cables-and replace any defective ones-then check that the battery cable clamps are clean and tight. Any battery should be tested for condition it replaces when it fails. The cause of your problem will be to examine the starter solenoid wiring and connections, and check the starter mounting bolts and the fusible links coming out of the engine compartment for burns, repair the circuit. Check the gear position switch or clutch start circuit systems, and verify the ignition switch circuit is working correctly. If the ignition switch is cranked and the starter does not actuate, then check for battery voltage on the solenoid to ensure it is getting the proper voltage signal that is needed. However, if voltage is present yet the starter motor does not move remove the starter motor and perform a bench test. Connect a voltmeter and an inductive pick up ammeter to the battery to see if the cranking voltage and current draw are as they should be; if the starter turns over slowly and the battery is in good condition and the terminals are clean. If voltage reaches the starter and it does not come on, test the starter/solenoid assembly on the bench, as it is possible that the solenoid is bad. Testing the solenoid is easy when the assembly is mounted in a vise, connect jumper cables and see if the pinion drive extends but does not turn, then the starter motor is bad, or if the pinion drive does not move with a clicking sound then the problem is with the solenoid or starter motor. Assuming the solenoid plunger extends and rotates the pinion drive, the assembly is good.