I'm experiencing a bad idle hunt under electrical load( idle between 5-600 to 1500. For instance when I have my head lights on or heat running full blast or ac on at all it will do the idle hunt. I have a brand new red top optima... and alternator puts out 14.5 v when electronics are off and when it idle hunts (only with electronics on) it drops down to 13.2-13.5 when the idle drops.
I have new battery, new ignition system. Car is at 48k. I thought maybe it could be neutral switch, but symptoms don't go away when clutch is mashed or in gear. I thought maybe a vacuum leak but it ONLY happens under electrical load like I said. So now I'm not entirely sure what it could be.... any suggestions guys?