Cross polar cap voltage saturation has been observed by various measurement techniques. An example of the saturation is shown in this paper and an explanation is proposed in terms of magnetospheric current behavior. The cross cap voltage saturation might be associated with either a voltage source or a current source effect since the cross cap potential and cross cap current are related by Ohm's law. The cross cap current is the difference between the Region 1 current influx to the polar cap boundary and the Region 2 current. Because, during high interplanetary magnetic field (IMF) -Bz conditions, the Region 2 current is significantly enhanced, the cross cap current, and hence cross cap voltage, is not anomalously higher than usual. Our measurements show agreement with Region 2 (partial ring current) enhancement during high IMF -Bz conditions.