I have a 1990 XJ with a 1996 engine and accessories. Ever since I got it, the voltage gauge always has read a little less than 14v. Today I finally put a DMM on it, at idle with no electronics on I get 13.78v. If I remember correctly, an alternator should put out around 14.5v, correct? With the headlights and A/C on it drops to 13.5 volts.
That said, I've never had any charging problems, and I don't have any aftermarket power sucking parts. (yet ) Should I worry about this? Is my alternator going out?