Every dark blue wire under the hood gets 12 volts from the ignition switch. There were a few years when they used red wires on the trucks instead of blue. If the original wire at the alternator is snipped off, you can find the same circuit to tap into at the ballast resistor on the firewall or the choke heater.
Here's a drawing of the entire circuit. The only thing you might want to check on your alternator, if it's a used one, is both field terminals must have insulating fiber washers under the screws for the brushes / terminals. One of the two terminals was grounded on the 1960 - 1969 models with the mechanical voltage regulators. The 1970 and newer models can be used on those older cars if one fiber washer is replaced with a metal one. It's very rare to find the older style but it's still worth mentioning.
On the alternator, the blue and green wires can be plugged into either terminal. The voltage regulator has to be bolted to the body because the ground is one of the necessary connections.
Mar 4, 2011 at 7:41 PM
