02 cummins overcharging after external VR installed

[Jesnic]

Ordered a PCM from Auto Module Source today. I sent them my vin # and all pertinent info and they said no problem. Should I erase all codes before changing it out? I also orderd the ECU as well, just to be sure. It just really doesn't make any sense as to where the gauge would see the voltage increase and trigger the check gauge lamp when the alternator is taken out of the circuit. The PCM is generating this signal from somewhere and sending it only to the gauge, nowhere else.

[Jesnic]

I just replaced my pcm with a reman one, programmed with my vin, mileage, etc... I removed the external VR and wired everything back to factory. The voltage is back on line where should be. Everything seems to be running as it should. I still have the 0622 code and the 1765 code. Maybe they will go away after a few key cycles or warm up cycles? I left the grid heaters unhooked for now and will monitor. Mike, what does it take for the truck to erase the codes itself?

[will]

Has anyone else run into this issue? Having the exact same problem with a 2001 3500 5 speed truck. It's the service truck at the farm I work for... Literally the exact same situation...Thanks!Will

[will]

If anyone else has this issue, swap to a ford style regulator, it fixes the headlight flicker, the radio noise and the overcharging all at once.The ford regulator modulates the power to the field instead of the ground, it also senses voltage from the 12+ post on the alternator and has a separate turn on lead. Wish I had done the ford regulator from the beginning.

[Mopar1973Man]

I just replaced my pcm with a reman one, programmed with my vin, mileage, etc... I removed the external VR and wired everything back to factory. The voltage is back on line where should be. Everything seems to be running as it should. I still have the 0622 code and the 1765 code. Maybe they will go away after a few key cycles or warm up cycles? I left the grid heaters unhooked for now and will monitor. Mike, what does it take for the truck to erase the codes itself?

40 warm up cycles to self erase codes. I would personally just erase the codes with a OBDII code reader and take it for a test drive and then check again to see if the codes returned. If so then you'll have to deal with the codes.