Chrysler Repair: 00 T&C: Charging light on but alternator OK., PCM or ?, voltage light, controller module

Question
My 2000 TC 3.3L V6 died on my way home the other day -- My battery/Voltage light had come on about 15 minutes prior to the following: I turned the headlights on while I had the radio on and the radio went out. I turned the lights off and the radio came back on. I had been slowing down at this point and the trans had shifted down -- I was going about 25 mph. I tried to turn the lights back on as I was accelerating -- the radio went off and the trans would not shift into next gear. I turned the lights and radio off and made it home at 25 mph -- with-in 2 1/2 miles. When I got home I tried to restart and nothing, the battery was dead. I charged the battery to a full(?)charge drove to advanced auto to check the charging system (9 miles one way).  The battery was good the, the starter was good and the alternator/charging system was good.  The Batt/Voltage light had gone off and I was hopeful everything was ok (even though the battery was old). The following day I drove to WalMart about 20 miles away and the Batt/Voltage light came on again. I had the charging system tested again and the battery needed replaced while the rest of the system tested good both with the old and new batteries.  I drove around about 55 miles total and the Batt/Voltage light came on again.  I got home with no problems and everything seems to be running fine with the new battery, save the Batt/Voltage light on.  I hooked my new battery to the charger and the battery was still not at full charge after 3hrs at 6 amps. I checked wiring connections and all seems fine except some build up that was on the negative connector to the battery that was cleaned before I charged the old battery. So is this a bad voltage regulator?  Is the voltage regulator in the powertrain controller module? And can it be replaced separately? Or is it in the PCM?  How would I replace the VR or the PCM and what can I expect to pay for the parts and programming the PCM?

Thank you for your valuable time -- P

Answer
Happy New Year, Philip!
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The voltage regulator circuit is built-in to the pcm and is no longer a separate part that can be replaced. But before I would suggest replacing the PCM I would believe that you would do well to have a fault code readout of the pcm to see what it thinks is wrong. An Autozone parts store will read it out free, and maybe so too would Advanced. Let me know the codes and then we'll go from there. The charging circuit is not complicated: just a wire from the pcm to the field coil of the alternator is either grounded or not to either charge the battery or not, and voltage has to be applied to the other end of the alternator field coil by a wire. It may be an intermittent connection of one or the other wire or am alternator that is getting flaky.
But when you write back tell me whether you have a fuse box under the dash or not. At some point between '99 and '02 the fuses were all gathered into one box under the hood, and I have the circuit diagrams for both set-ups, but I don't know which you have in an '00. Another way to tell would be to look at the plugs on the side of the electical power box under the hood next to the driver side inner fender, and see if it has 8 or 9 large plugs (tilt box to access rear side to see plugs). Let me know which.
Roland
PS It could also be an intermittent short circuit that is dragging down the charge rate to the battery and discharging the battery when at rest. That too needs to be tested for with a voltohm meter when the symptom is occuring (the warning light in 'on'). So let me know if you have such a meter and I can tell you about testing the next time the light comes 'on'.