My car ran out of voltage while my Dad was driving it.
I did what every person should do, and checked the voltage coming from the alternator. It was not charging, so, obviously, it was bad. I got a new one, and put it in. The new one didn't work, either. It happens. So I took it back, and had it bench tested. It was working fine. I had them do it again. It was fine.
So, I put it back on the car, and it did not work 
Hmmm. I tested the "S" wire going into the harness, which tells the alternator to start working. It was working. 
NOW what
This is the point where every good mechanic starts desperately poking at random things in the area. I shook the wire harness. I got underneath the car, and took the belt off again. I spun the alternator pulley. With my mind wandering, I laid underneath the car. I poked the other belt. I was like an infant playing around with a mobile in a crib, pulling, and pushing things. I spun the crank pulley with 2 fingers... Wait a minute. I don't think that's right. I spun it again. It ran smooth, and quiet. The inside part stayed stationary. That definitely isn't right. I felt like one of Romney's "Smart people" when I exclaimed to myself "That's not supposed to happen!" I was sure of it; If the crank pulley spins freely, it can't turn the alternator. So there you have it. The outer part of the crank pulley had separated from the rest. I have never heard of that happening before, and I have worked on many, many cars of all types.
So, on Friday, I'm finally going to put on my underdrive pulley with Mooneggs' help.
