Battery cables or connections are loose, broken, or corroded (excessive resistance)
Check the battery cables and connections. Refer to Procedure 013-009.
Battery cell is damaged (open circuit)
Check the condition of the batteries. Replace the batteries, if necessary. Refer to the OEM service manual.
Voltage regulator is malfunctioning
Check the voltage regulator. Replace the voltage regulator, if necessary. Refer to the OEM service manual.
Electronic fault codes active or high counts of inactive fault codes
Read the fault codes with an electronic service tool. Refer to the Troubleshooting and Repair Manual, CM21 00 and CM2150 Electronic Control System, Bulletin 4021570.