So, wait.. if the voltage regulator is in the pcm and not in the ECM. Then changing ECM wouldnt have any effect on any of the voltage outputs? So id still be screwed?That is often due to bad solder connections inside the ECM for the switchover to low lead solder 20 years ago. If testing by swapping ECM's they have to be the same Cummins PN on a sticker usually on the back side of it. 98.5 and 99 are all the same, and from other years do not work.
Yes regulator is in the PCM but not related dto ECM or running so long as voltage is over 12v.