Hello all, my 2003 Silverado recently sat for one week while I was away. Returned home and found that the battery was dead. Discovered a pretty badly corroded and loose side terminal stud { negative side }, just replaced the terminal stud and drove for 45 minutes so the computer can relearn the idle codes { yes, it was stalling a lot at stops lights, etc} Idle is a bit better now but during the drive time I noticed the battery gauge needle fluctuating up and down. When the truck idles low, the needle drops, lights dim, heater fan slows down, etc. When going faster it stabilizes at around 14.5 volts. Come to a stop again and she drops once again. Tested battery with a voltmeter immediately after shutting engine off, it reads 12.57. Truck ran just fine before I went away for a week. Now, will the battery needle fluctuate during this idle relearning stage??