Variable Blower Control
WARNING: This page is about a different car, the 2008 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.
The variable blower control is located on the cooling unit. The variable blower control receives a gate voltage from the A/C auto amp. to steplessly maintain the blower motor voltage in the 0 to 5 volt range (approx.).
Courtesy of NISSAN MOTOR CO., U.S.A.