Electrical problem

Electrical problem
August 30, 2010
Every light inside and outside of the van pulsates at idle and any speed. I checked the battery and the charge is good and no problems with starting or the engine running. I then replaced the ELD (fuse / relay box under the hood) and the lights still pulse. I have not changed the alternator because the battery keeps a good charge and the engine runs good. If it is the alternator, can the alternator be rebuilt? If it is not the alternator, what could it be? Thank you for your help.
December 3, 2010
I had the alternator load tested and the test came back normal, I had the battery tested and it came back normal. Now what do I do? Thank you for your help.