If your Chevy Silverado is having problems starting, the starter motor can be a possible cause. This may not be the issue, however, and there are other areas of the starting and ignition system you should inspect before you troubleshoot the starter itself. The problem could lie in the starter motor or its solenoid. You should start by testing the voltage on the starter, which may lead you to performing a bench test on the starter.
Inspect the condition of the battery cables and their clamps. Make sure they are tight where they connect to the battery terminals.
Test the battery's condition, connecting a voltmeter to the battery--red probe to the positive terminal and black probe to the negative one. Make sure the voltage is greater than 12.5 volts.
Check the starter solenoid's wiring connections; use the wiring path described in the Tips.
Connect the starter solenoid switch terminal to a voltmeter or a test light. On models made in 1999 or later, this is the one with the small purple wire.
Have an assistant turn the truck's ignition switch to the "On" or "Start" position while you observe the light or voltmeter. Check for the test light to shine brightly or voltage to appear on the voltmeter.
Check the starting-system circuit if voltage does not appear, taking into account the wiring pattern described below.
Crank the engine and observe the battery voltage if the starter turns over slowly; the voltage shouldn't drop below less than 8.5 volts. Connect an inductive-type ammeter to the battery and observe the starter's draw on the battery; it shouldn't exceed 400 amps (350 for models made before 2007).
Remove the starter and mount it in a bench vise for a bench test if voltage appears on the meter/light but the starter motor will not operate.
Connect the starter's B+ terminal to the positive terminal of a test battery using a jumper cable. Connect another jumper cable to the battery's negative terminal and the starter body. Connect a spare starter switch to the positive battery terminal and the solenoid's S terminal.
Apply battery voltage to the S terminal using the starter switch and see if the solenoid plunger extends with the shift lever and overrunning clutch and then rotates the pinion drive
Replace the starter motor if the pinion drive extends but doesn't rotate--the starter is defective but the solenoid works. If the solenoid clicks but there isn't any movement, the problem could be the motor, the solenoid or both.
