The alternator has nothing to do with starting the engine unless it's not fully charging the battery. Next time we'll do a simple voltage test to determine that.
What we need to do now is figure out if that click you're hearing is the starter relay or starter solenoid. Listen by the starter to tell if the solenoid is clicking when a helper turns the ignition switch to "crank". If it does, but the starter doesn't spin, the contacts inside the solenoid are pitted and burned away or the drive gear is sluggish and sticking.
If all you're hearing is a real light click from the relay, measure the voltage on the smaller wire on the starter solenoid. You should find 0 volts at first, then it should go to full battery voltage when the helper turns the ignition switch. If the starter doesn't spin that will be over 12 volts, but if it does crank it will be around 10 - 11 volts. That's normal.
When it doesn't crank, if you find 12 volts on that smaller wire, replace the starter. If you don't have any voltage there, suspect the starter relay or a poor connection in that circuit.
Dec 20, 2016 at 5:40 PM
