ive known for a little while that my stock alt was getting weaker but i didnt know it was as weak as it is. this morning when i left to go to class it struggled turning over. and then on my way home it was raining so i had the windows up, a/c on, headlights on, wipers on, and my system on at about 1/3 volume and i happened to look down and all the dash lights were kind of dim and the battery light came on, so i turned everything off, put it in neutral and revved it up to about 2200 rpms and the light went back off within about 30-45 seconds. so i decided to go to the auto parts store and buy a cheap voltage gauge so i can keep an eye on the voltage. i hooked it up to the accessory wire since this one doesnt have a remote turn on or anything like that, its on or off, and its showing about 12.5-13 volts on the gauge with nothing on, and with the a/c on about 12.5 and then when i turn the headlights on with the a/c it drops to 12 volts. so now i need an alternator, great.
tl;dr - my voltage at idle is 12.5-13 with nothing on, my alt. sucks, and i need a new one.