I have an 05 Crown Victoria and when I blip the throttle the voltage will jump to 15+ volts for a brief second, I put in a brand new alternator and it still does it, wondering what the issue could be. It charges at 14.7 and will get as high as 16v despite having the old or new alternator installed. Brand new duralast agm as well. Could this be a pcm issue or a short from the alt pigtail to the pcm?
Sorry for the late reply just got to diagnosing today, most of the fuses read .014V but I did notice they will jump from .014v to .017v whenever the compressor engages?