The earliest version of this charging system is identical to the rear-wheel-drive version with one important exception. The same Chrysler alternator design and firewall-mounted voltage regulator were used, but the alternator was mounted on rubber bushings to isolate it from engine vibration. Since it was insulated from the engine, a braided ground strap or a large diameter ground wire was used between the engine block and alternator housing. It was fairly common for that ground strap to corrode off or for the wire to get overlooked when it was removed for other service. That will result in a no-charge condition. If your voltmeter negative test probe is grounded to the engine or battery negative post, you will read normal voltages on the two field terminals and the output terminal on the alternator. The clue is you will also read full battery voltage on the alternator housing. Voltage on the housing tells you to repair the ground circuit. For operation and testing of this system with the external voltage regulator, see "Chrysler Charging System, 1970 - 1989".
Later versions incorporated the voltage regulator inside the engine computer. Chrysler's name for that is the "Powertrain Control Module", (PCM). Most models supplied battery voltage to one field terminal through the ignition switch. Beginning in the very late '80s and early '90s, various models began supplying the filed current through the automatic shutdown (ASD) relay. For actual troubleshooting, both circuits are treated the same way. The same circuit feeds the ignition coil and possibly the injector(s), so if the engine runs, there's no need to look back further than the splice in the feed wire if voltage is missing at the alternator field terminal. If there's a problem in the ignition switch or ASD relay circuit, the engine won't run so you won't be diagnosing a charging problem.
What you must be aware of is the ASD relay only turns on for one second after turning on the ignition switch, (that's when you might hear the hum of the fuel pump). It turns on again during engine rotation, (cranking or running). That means you must have the engine running to perform voltage tests in the field circuit. Some early versions used a large Bosch alternator. Later versions used the little silver Nippendenso alternator. For operation and testing of this system with the voltage regulator built into the PCM, see "Chrysler Alternator, Late 1980s - Early 1990s FWD Cars".
Since there were quite a few variations between alternator suppliers and circuits, you might want to visit the AllData web site and purchase the service manual subscription specific to your vehicle. The cost is $44.95 for five years, less for a one-year subscription, and includes access to much more information than is found in the manufacturer's paper manuals and at about half the cost.
Interpreting the Test Results (Chrysler Charging System, 1978 - 1990, FWD)