I have a 1994 jeep cherokee sport, 6 cyl. 4.0 liter 200,000 miles. I just changed the alternator after getting it tested and finding out it was bad. Everything things seems OK now (It's cranking normally and the " check engine" light has gone out) the only thing I noticed is that the charging gauge reads 14 when I am driving but when I am idling it is charging at about 11-12. Could it be that the drivebelt is not tight enough? I did not have a guage to measure the tension on the belt which is a serpentine belt. I did however mark the adjustment bolts posiition before I loosened it and I tightened it back to that position. What do you think?