Question on HV fan function

On a Gen 2, the HV battery fan pulls air from the passenger compartment through a vent grate located shoulder high at the rear passenger seat, RH side of the seat. The fresh air blows into the top of the HV battery, down between the individual modules and into the bottom plenum, where it exits the passenger side of the case and goes rearward toward the 12v battery. It exits the car just forward and above the battery, through a louvered opening in the side of the body. The ductwork that exits the bottom of the battery case has a fan control unit mounted in the side of the duct (identical to the unit for controlling the normal vent fan in the front of the car). The top duct has the fan relay clipped into a mounting tab/hole.