Vehicle power supply system

A vehicle power supply system includes a control unit for controlling to turn on and off first to fourth switches. In a normal state, the control unit turns off only the third switch to supply electric power from the first power supply unit and a power storage unit to the first and second load units. When an abnormality occurs in the vehicle power supply unit or the first load unit, the control unit turns off only the first switch to supply electric power from the power storage unit to the second load unit. When an abnormality occurs in the second load unit, the control unit turns on the first and fourth switches and turns off the second and third switches to supply electric power from the vehicle power supply unit and the power storage unit to the first load unit.