I recently had to buy a new battery for my '05 GTP. A couple of days later, after it started raining, my windshield wipers were very sluggish. When I checked my voltage, it was down to 12.8V, so I figured that the alternator had went, and subsequently taken the battery with it.
After the alternator was swapped, I still had my volt meter up on the DIC. Next day, as I'm going down the road, I sat and watched the voltage go from 14.8 to 12.8 in .1V intervals within the first 5 minutes of driving.
My mechanic disconnected the battery again, did a couple of tests, reconnected the battery, and it was ok again for the first day, but then on the second day, the voltage dropped again, identical to as before.
If the following is worth anything to help: during the battery and alternator changes, my mechanic used one of those memory saver devices that hooks into the scan tool computer port under the dash; only thing it saved was my radio station presets. Also, when he hooked his scan tool up, it would shoot traction control, and even a stabilization link errors to the DIC. At one point, he plugged it in, turned the car to on, and it stayed dark. When he wiggled the connection, everything came back on, and shot the same errors to the DIC (shutting the car off then back on took care of the errors, and they never came back).
Do you think I'm looking at a computer failure, as it's not telling the car to charge? I personally don't think it's a wiring issue, as it would be seen right away, and not a day later in such a slow, methodical manor. Think a full battery disconnect for about 20 minutes would help/hurt (even though I've heard rumors that if the battery is disconnected for too long, it can cause throttle position issues)?
Thanks for any advice in advance!!