The above scenario is about starter circuits. The starting circuit of a car malfunctions for different reasons; therefore, it would be wrong to always assume that the problem emanates from a defective starter. Before investigating the starting circuit in depth, we should also examine the connections between the battery cable clamps and battery terminals making sure they are clean and tight. Replace any damaged ones among the battery cables. However, if it does not pass any tests, then it is supposed to be replaced. Evaluate the connection of wiring and connections to the Starter along with the tightness of its mounting bolts. Check out related fuses in the engine compartment (fuse box) that might have blown off. Assessing the ignition switch circuit as well as ensuring appropriate operation of the starter relay situated in underhood electrical center is equally important here. Moreover, these systems must work properly so that power can be safely delivered from battery to relay for starting purposes; meaning, you also need to verify functional condition of Park/Neutral position switch. When you start your vehicle by turning on ignition key from OFF to START and nothing happens (starter stays dead), look for voltage at this location on solenoid so as to verify whether or not such voltage is supplied by relay through them. Keep an eye on what happens at this terminal during an assistant's activation of ignition switch using a 12-volt test light or voltmeter; bright test light or indicated battery voltage on voltmeter confirms presence of voltage. If there is no one present or absent when checking fuses, ignition switch, starter relay or its wires then there is a problem with either fuses, ignition key switch, relay or its wiring respectively where no voltage should be found according to my paper. There are other possibilities that may occur when voltages are available at these two points but motor does not engage when rotating crankshaft pulley by hand after disconnection from load side system termed as rare case. In testing, use battery test clips to connect test battery to starter terminals and then apply voltage from it on S terminal solenoid while observing pinion drive and any movements of solenoid during such actions. The solenoid is working if the pinion drive extends without turning; in this case, however, the problem lies with the motor because it can't turn around when energized by the solenoid. If you hear clicking sound but there is no movement at all, one or both of the solenoid or Starter may be defective. In this case though, you can tell that the starter assembly is good because it has a rotating plunger that extends pinion drive outwards.
