Until a year ago, everything was fine. Then whenever the headlights came on, the digital clock quit displaying. When headlights were turned off, the clock comes back on showing the same time as when the lights were turned on. At the same time when this started occurring, the AC would not come on if the temp was above 85 OR if it did come on, it would turn off if you used anything electrical (Use turn signal or lower a window). Have had AC system checked and replaced alternator but to no avail. I honestly believe it is an electrical (voltage) problem but don't know where to start looking. Not like the old days where you replaced the voltage regulator! HELP , PLEASE!!!!