I have a 2001 Dodge Ram 1500 with the 5.9 gas in it. I recently installed an external voltage regulator on the truck due to the pcm losing the module for the regulator. After installing the regulator I noticed that sometimes my voltage gauge will max and the check gauges light will illuminate. I used a volt meter and found the battery was putting out 14.5 volts while the gauge was still reading 18volts. The way I installed the external regulator is I cut the plug off of the back of the alternator and wired the plug into a homemade harness for the regulator. Ran the top center wire into 2 wires and ran one to a keyed ignition source and the other to the alternator plug. Grounded the regulator from its case to the case of the alternator. I taped up the old wires that ran from the alternator to the pcm. Has anyone else had this issue before? I’m unsure if thenguage is maxing because the pcm isn’t reading voltage, but that doesn’t explain why it doesn’t do it all the time.

ive tried googling it and to no avail have I found anything regarding the issue im having. If bu chance you could point me in the right direction i would appreciate it.