Nissan Sentra 1993 Electrical Problems help!

Please help me. I have been experiencing massive electrical problems with my vehicle. Over the past year or two, I have had the alternator and battery changed almost 4 or 5 times. I most recently had a problem where once I shut off the engine, the clock would shut off and everything would basically lose power except for the headlights. I had it checked a few months ago and a short in the cigarette lighter was detected and fixed.. Now the problem has returned. Could it be the voltage regulater? I don't know what else to do. That kinda sounds like a computer problem. Remove the connectors and see if there is any corrosion or water on any of the terminals.Car Repair Talk's forum.