Hello!
I had some problems a while back with an electrical gremlin running amuck in my 95 Zetec, and one thing I learned is never take your electrical parts to AutoZone, advance, orielly's or apparently any parts store! I went to three different stores with my alternator and I got three COMPLETELY different diagnoses! Never mind NONE of them was correct! (all of which, by the way, were followed with the suggestion to buy a new one -"Oh, sure, we've got that $180 part in stock!") What I learned was to take your parts to a starter shop to have them tested. They'll test for free and in my case all I needed was new brushes ($20).