The alternator is showing a couple of troubles. The voltage will sometimes be steady and at a normal 14 volts, approximately. At other times, the voltage will fluctuate fairly rapidly, noticeable by lights flickering from bright to dim, and periodically spiking to 15 volts +/-(lighting the battery warning light). Then the alternator will quit charging altogether.
I have cleaned the connections on the battery terminals, the starter, and ground points on the block, firewall, and the body ground near the battery. I've checked the connections at the alternator. The small gray wire (reference voltage?), the large output wire, and