Ford Expedition charging system issue with battery light remaining on after battery and alternator replacement on Ford Expedition

Some Ford Expedition owners report experiencing persistent battery light issues even after replacing the battery and alternator. These owners have noted that the "Check Charging System" warning light may remain illuminated, indicating potential underlying problems with the charging system. Monitoring voltage readings is essential, as the alternator should output between 13.8 and 14 volts under load; failure to do so may suggest the alternator is not functioning correctly. Additionally, if the alternator is unable to support the vehicle's electrical load, it can trigger the battery light. Some owners have also encountered issues related to components like the resistor wire, which can affect the charging system. Furthermore, repeated deep discharging of the battery can impair its ability to hold a charge, contributing to ongoing warnings. It is recommended that owners conduct thorough testing of the battery and alternator outputs to identify any discrepancies that may be causing the battery light to remain on.