I have a 2001 Dodge 3500 and this thing has got a few issues. My lights are flickering at idle and the truck is running rough. Also my gauges the volts and temp gauge will go to zero then come back either by shutting the truck off or just driving it and coming back up mysteriously?? I have done the external voltage regulator swap and it help for a couple days, but then starting acting up. I know its not a ground issue because I have checked and rechecked them. The batteries are brand new as well a the alternator and they were both checked again to be sure. What do you guys think? Maybe the PCM crapping out? The only codes on the truck that I had was PCU 1594/1693 and ECU 0177/1693. The ECU one I think was because when I washed the dang thing the circuit that is hanging from the old fuel pump got wet. Oh and the IP pump is a new rebuilt one also and I checked for wires being shorted and nothing. Well let me know what ya think.

 

 

Thanks for your time!!

Steve

 

If you're sure alternator is not putting out exessive ac noise then for now 

Does sound like a lose wire or conection. 

You need a scan tool to monitor what the pcm is seeing for voltage.