I'm having a similar trouble on my Contour V6 98... but my battery light (new battery) is flickering at highway speed (over 70 miles and/or 3000rpm) so I assume the alternator cuts out (intermittent charges) but only at higher speeds?? Does this mean it will not necessarily show a faulty system (below 14V) at low or idle? How would the service tech test and correctly diagnose a full load speed test? All my cables look new and tight and 64,000 miles sounds quite early to change alternator... Looking forward to hear from you guys!