My '91 5.0 runs poor and sometimes the car surges the second I turn the A/C on. When I turn the A/C off, the problem goes away completely. Also, when I am idling and turn on the A/C, the voltage goes down, and even further when I put the turn signal on. In the morning I don't have problem, but at night with the lights on and if I put my turn signal on, the volts drop a ton. These are very annoying problems and I am looking to see if anyone has had this problem or has any info on how to fix it. Thanks