Upper and lower pressure equalizers couple to a lower end of a motor of an electrical, submersible pump assembly. An intermediate connection having a liquid flow passage connects the pressure equalizers. A connection valve located in the liquid flow passage closes the liquid flow passage prior to connecting the pressure equalizers with each other, and opens the liquid flow passage after the connection between the pressure equalizers is made. A sensor lower equalizer wire extends from a sensor unit through the lower pressure equalizer to a lower electrical terminal at the upper end of the lower pressure equalizer. A sensor upper equalizer wire connects to the lower electrical terminal and extends through, the upper pressure equalizer to an upper electrical terminal at the upper end of the upper pressure equalizer. A sensor motor wire extends downward from the motor into engagement with the upper electrical terminal.