voltage fluctuation

[MethodFX]

i've been having a problem for awhile that's got me totally shot - i have a voltage meter in the car and the needle bounces around sometimes. it'll go from 14.5v with vehicle running down to 12v then to 13v to 12v to 14 ... it only stops bouncing around when i rev the engine to 3,500 rpm. it'll read 12.5v with the car at idle also. my headlights dim pretty easy as well. i've checked out the ELD and have tried 2 alternators that were both good and still the problem the won't go away. anyone have any ideas, i'm lost. my interior lights also pulse with rpm of the engine(they pulse faster at 3,500 than they do at 1,500).

any ideas would be VERYT helpful!

[pwrusr]

are all your gounds in good shape?

[MethodFX]

i redid the ps/alt bracket and valve cover grounds with 8ga ground wire and used a dremel with a wire brush bit to burn off the metal where they bolt, did the same at the battery ground location. the ground eyelets were crimped/soldered onto the wire! i tried to eliminate the grounds! i don't know if the ELD or ECU might be faulty