I know for a fact the internal voltage regulator is going in my 2001 with all my tests and new parts. Yes, the alternator is new,both batteries and the wires are good, as well as the grounds.  I know the regulator is internal in the computer and are contemplating on doing a external modification to solve it, but are unsure. Has anybody done this mod to their truck and have any bad effects? I am looking at the kit at Alternatoparts..com and it looks pretty simple. The part number is ERCKFRM.

 

I am thinking that this is why my automatic has been acting up. It all of a sudden started to stutter. I am sure the signal/voltage  between the PCM and APPS is being effected somehow. Just thinking out loud. Maybe I might be wrong and someone would tell me.

 

Thanks for any info!!

Steve

There was a guy here that did this mod a couple yrs ago and had trouble with it. I'm not sure who it was or what VR he used but know it can be accomplished fairly easily

The problem is the extrenal regulator is prone to over charging the batteries. The PCM regulator has the battery temp sensor and is capable of adjusting the voltage based on battery temperature so cold batteries like extra voltage where hot batteries like less voltage to stay cooler. The external regulator bases it value off of under hood temperature which is OK. But if you got a battery with a cell issues starting the batteries tend to boil over throwing acid all over the fenders and hood. This is a reason why I don't like that mod but it does work in a pinch.

Thanks! So it is the PCM, thanks for clarifying that. It rarely gets cold here, probably out of the winter months maybe a couple days in the thirties. The rest in the sixties. Now the other months out gets sickening hot.

As for the batteries I replace them about every two to three years due to the heat and alot of driving. Lol I would think being a work truck with the external it should be fine then.