[Opera House]

One problem that it can be is the grounding from the engine block to the car bady. Remember that the engine is basically isolated from the body by engine mounts, the only electrical connection being a poor one through the bearings. In older vehicles these ground connections can go bad. I heard of one newer Explorer where the ground screw was never tightened. Try an extra ground wire from the b;ock to the body. Another problem has been corrosion on the 15A fuse that supplies the alternator regulator.