Had this problem awhile back and took the advice of installing 2/0 welding cable from the alternator to the battery. Problem still persists when the car is idling. With everything on, the car still idles fine and nothing seems to change. Haven't driven it yet though. With the smaller wire previously installed, I had a few issues, but not anymore. Just my ECM is reading low on the volts. Multimeter at the battery and the alternator post is 14.5. With everything on it's 14.3. I'm getting a solid 12 volt reading from the pink wire going to the ECM. Should I be concerned? Thanks again.