To determine if the starting system is functioning, you should first investigate the cleanliness and firmness of 
Battery Cable clamps, check out the state of battery cables, determine if the battery is in good condition, inspect connections as well as wiring for the starter motor, confirm tightness of starter motor mounting bolts, test each fuse found at engine compartment fuse box, inspect ignition switch circuit, examine starter relay among other things and ensure that clutch start switch or Park/Neutral position switch are in their right operational conditions. For this reason try to verify whether voltage is arriving at the starter by attaching a voltmeter or a test light to purple wire through solenoid while turning key to start position. So if your starter moves slowly, then check how much cranking voltage it takes from a battery while on an engine. In addition to having clean terminals and cables with good cold-cranking rating for that purpose; your battery must be in excellent condition too. Before testing your battery and engine block in cases of extremely cold weather conditions heat them up first. If there's power reaching it but not being used remove the motor assembly from its bench and test it. You can tell whether there are any defects within this part by checking what happens when solenoid plunger shifts lever overrunning clutch for proper operation are activated. Some starters may work when we connect them electrically to pinion drive but they fail to rotate that means such motors need replacement because solenoid have electricity so it is fine; otherwise these starters will be unplugged completely since no movement will occur when solenoid clicks mean either one might be malfunctioning while another has failed completely. With this in mind; you can conclude that once you pull out plunger which extends rotates pinion drive starting system functions appropriately.