I have a 2003 7.3 f350 crew cab 4x4. In the last 6 months one of the batteries stopped charging. We have replaced the alternator twice, the batteries 3 times, but we continue to have the problem. It acts like a loose wire since before everything shuts down, the battery signal will flash on and off, especially going over bumps. Nobody has been able to find the problem. Does anyone have any experience or suggestions?

Remove and fully charge each battery, clean the battery terminals and cable connections, and inspect the cables for hidden corrosion and/or breaks. Check each cell with a hydrometer or multimeter. Also, thoroughly clean the ground cable, especially where it bolts to the truck's body. I would also clean the connectors on the end of the wire going from the alternator to the battery with abrasive cloth.