I would think the first thing to do is to verify that the system is not charging and perhaps if referencing a dash gauge, it could be damaged. Due to the number of components in an OE charging system many have opted for a simpler system with one wire alternators. As stated earlier, you really need a multi meter to check for voltages at various source starting with fuses/fuseable links. I can see your frustration if all components were recently new but that doesn't mean a component has gone prematurely bad. Battery should be around 12.8 v with no cables connected. With cables connected and engine running it should be higher, about 13.8 volts. Output on the back of the alternator + post with the car running should be above 13.8 and possibly up to 14.2 to 14.5. As you turn on loads like lights, heater etc the output will vary depending on battery charge but should still be well above 12.8 volts. You can pull the alternator and have it tested at most auto supply outlets to eliminate it as the problem. The voltage regulator is a different issue and are tough to diagnose without doing substitution. I run a Ford 3G 130A unit that bolts right in. It can be wired as a "1 wire" or as an alternator with "load sensing" by merely changing the plug-in internal regulator for about $24. The volt gauge in the car shows a steady 14.2 volts under all conditions with electric fan, fuel pump, headlights, heater and brake lights on. Doesn't come much better than that. I suspect one of your charging components has gone south ( including wire connections) but you'll have to dole out some cash to find out which one. If you opt for single wire they are available that look just like original OE ones.
Turn on ignition, pull wire off right side of regulator. You should see small sparking.
I did pick up the manual...I'm going to need it! Used to know a good Mopar guy but he moved away so I'm kind of figuring it out as I go.
