No alternator output

Since it is the PCM that contains the voltage regulator and when bench testing that alternator and it passing the test, because the PCM is not included in that test leads me to believe that the problem just might be with the PCM and the voltage regulator function within it.

Voltage regulators are only in the engine computer on Chrysler products. They do that so the computer can adjust target charging voltage for a variety of conditions including air temperature, wide-open-throttle, AC on or off, etc. Other vehicles do this too, but with additional wiring and connector terminals to potentially cause trouble.

For GM's system, start with the basics. Does the "battery" light turn on when you turn on the ignition switch? If it does, the "turn-on" circuit to the voltage regulator is okay. The regulator is built into the back of the generator and is just about impossible to replace, and it is impossible to bypass it like you could on the 1986 and older models. Next, does the "battery" light turn off once the engine is running? If it does, measure the voltage on the large output terminal on the back of the generator. It must be between 13.75 and 14.75 volts. If you do find that, measure the battery voltage. It should be exactly the same. If you find closer to 12.6 volts or less, the generator fuse is blown. On newer vehicles like this, that is a large fuse that's bolted into the under-hood fuse box.