I just bought a 72 Jimmy, and I'm having good old electrical problems. The lights pulsate when the car is running. Last night I blew my running/tail/instrument lights fuse. The headlights and turnsignals still worked, but also continued to pulsate. What could be the problem? I'm thinking alternator diode or the voltage regulator. Any info would help???? Oh yeah, you can hear the engine surge with the hood open when the lights flicker. It follows the same beat.