Overcharging Coffee Grounds

So I sit reading here with coffee about the variances with Overcharging and causes such as Grounds..

2001 XJ Sport
I have two blue tops with a splitter/regulator
I have the large alternator from a Grande Cherokee in my Sport

My gauge goes into overcharge within minutes of running the truck..sometimes it will go back to normal for a bit, sometimes it stays maxed out on the gauge my whole drive.

Questions on solutions..
Braided grounds as opposed to a larger strait wire ground like a battery cable..

Create a separate regulator?

Replace PCM?

Do any of these make-shifts last and do they really SOLVE the problem that created the event to begin with?
For instance..
Is the larger Alternator causing the issue with the PCM if the PCM is on my sport and not from a Grande Cherokee?

Too much coffee?
Hate to go around in circles before seeing what variables have taken others on destructive paths.

were you having overcharging issues before you installed the GC alternator or after? you might have a bad GC alternator.

If the gauge shows High or Low Voltage on the dashboard, you have a mechanical issue with the charging system. Wires, grounds, battery, or alternator. Test and inspect each component

Running the larger alt with no issues fwiw..

I run the Alternator from the ZJ in my Heep with zero isues. Perhaps, one has to suspect the splitter.

Put the system back to the "stock" configuration and see what happens. If all is well with only one battery in the system and the splitter out, it is a "Well there you go" moment. Once you can get the symptoms to change, you have the problem in hand.

All good stuff! I have a ground issue for sure. I loosened and tightened all my grounds and checked my connections and my splitter and all of a sudden my charger shows two charging batteries, no engine light and a a perfectly centered voltage gauge.

So grounds do cause some abrupt issues with a small effort to fix.