Variable Blower Control
WARNING: This page is about a different car, the 2018 Nissan Titan XD and 2018 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.
The variable blower control controls the speed of the blower motor by controlling the ground circuit of the front blower motor. The A/C auto amp. provides voltage to the gate of the variable blower control based on the position of the blower control dial. The variable blower control is a metal-oxide semiconductor field effect transistor (MOSFET) that varies the ground side current of the front blower motor. By applying a variable voltage to the gate, the variable blower control controls the current flow to ground, thereby controlling the speed of the front blower motor.