hello, I'm sure this has been posted before, but I did a quick search before posting and couldn't find a post with the problem I am experiencing. I replaced the belt idler pulley due to it making noise and the bearings feeling rough when pulley was free spun (belt off). After replacing the idler pulley and putting everything back together the battery light illuminated and stayed on (it still is on or stays illuminated). I tested the battery and it failed. Replaced the battery with a Sam's Club Duracell 58 (group size) battery. The battery light still didn't go off. So I drove to O'Reilly Auto Parts and Autozone to have them test the charging system. Their tests indicated that my charging system passed. I went home and took off the alternator to get it bench tested. The bench test was performed twice and the alternator PASSED. Any ideas?? Please help. Thanks in advance. P.S. This is on a 1997 Ford Ranger XLT (extended cab) with the 4.0liter V6. Feel free to ask any questions. Thanks.