You are correct, Jeeps tend to be the same way, the voltage regulator is part of the PCM, but that is an easy enough fix, just slave in an external regulator. I had to do that as part of troublehooting an 98 Cherokee a couple years ago. I kept getting told that the trouble was in the voltage regulation, had the alternator tested by a reputable local shop, twice, and they swore it was good, slaved in the external voltage reg, same issue. finally I got under it while running & tested at the alt, initially good, then a few minutes later, nothing. I replaced the alt & all was good, pulled out the external voltage reg & spliced the wires back into the PCM, all still good. Anyway, the external vreg was all of like $22 I think, so that is a non issue...