On my 3.1, I took ANOTTHER alternator back to AZ within 2 weeks. At first, the original (non AZ) alternator was overcharging my battery to 17 volts. Replaced that one with the 1st AZ alternator. Ran for 2 weeks. Volt gauge started jumping again. Went back and they said bad battery. Car sat for 3 days until I got another battery from AZ. Put battery in and the alternator STILL fluctuated. OK.... drove to AZ and they did a test and said the alt. was overcharging and I swapped in the 2nd alternator. It tested ok at 14 volts while the car running. QUESTION... if the original battery was screwed by being overcharged with the original alt., did that battery mess up the 1st AZ alt. causing the regulator to possibly go bad? Maybe I got a bad wire somewhere? Ken

Well, as a general rule of thumb, bad batteries kill alternators and bad alternators kill batteries. However, with this day in age and everything being computer controlled, even something as simple as a loose wire can screw everything up. When you next go to check this out, clean off your terminals at the battery, the starter, and the alternator. Next, disconnect the battery ground cable (the thin one coming off of the neg terminal that runs to a screw right next to the battery), the ground strap (both ends!), and the 2 engine cylinder head grounds G102 and G108, and clean not just the terminals but the hardware as well. Make sure everything is tight when you connect everything up.

Oh, and another thing is that a lot of those reman alternators are bad right out of the box...