Originally Posted by
IBLUBYU
Since I've added a digital voltmeter in my XF, I've noticed a variation in the voltage being put out, while running, to be between 13.8 and 14.2. It seems to be higher in the beginning and tapers off as the car has run for a while. My question is....does our alternator/regulator, automatically adjust its output to the lower voltages after the battery tops up, and if so do all modern alternators do this? The voltage doesn't seem to be dependent on the rpms at the time. I never paid too much attention to the charging aspect, because most of the cars I've had utilize "idiot" lights. Just askin ...
I'd say you got it right.