Does not this system control field (regulator) by making available ignition power at one brush terminal, then modulating the field output (to negative) through the ECM? If the alternator battery stud has power, and one of the field connections has power when the ignition is switched on, then I would hunt from that point on. I never forget that there exists a possibility when all the tests have been passed that a "new" alternator may be defective. I hesitate to recommend full fielding this type of alternator even at idle due to the possibility of load-dump harming the ECM out-of-hand. An old fashioned tail light bulb makes a great temporary field control after all the tests above indicate an inoperative regulation circuit. Disconnect the brush connection entirely. Both wires and set it safely aside. Use a jumper test clip wire to bridge from the big battery stud to one brush clip. I use an 1141 bulb with a pair of 12" test leads to connrct the second brush lead to nrgative. Beware of shorting the two test clips connected at the alternator, together.
Start the engine and let it idle. Immediately consult either a test meter or the dash gauge. Then shut off the engine.
If the voltage rose the problem lies between the alternator field to ECM connection. If it did not, there is another problem.
Again, make absolutely certain that there is battery power at the main alternator output stud before you test. This pre-test is by far the most critical one to be made when diagnosing an alternator "no charge" fault.
Hope this helps. Computer ECM gurus tell me the MoPar reg is very very beefy.
