I have been fighting a battery issue for awhile now on my 01 GT. Originally I had a 4 year old never start that died because of age I am sure. I had bought a wrecked car from a auction that had a less than a year old napa legend battery in it that was dead. I took it to napa and they gave me a brand new napa legend battery that I put in my GT. Anyway that battery worked great for a couple of months. Then it got to where if my car sat for a couple of days it had to be jumped. Now if it sits overnight it needs to be jumped. I tested my alternator with my multimeter and it says it is charging 13.9 volts at idle and it falls off to 13.8 at around 1500 rpm's. From what I remember a alternator should charge over 14 volts at idle and increase as rpm's rise. Wondering if my memory is correct and if I should replace my alternator?