FRONT MANUAL AIR CONDITIONING SYSTEM : Air Flow Control

WARNING: This page is about a different car, the 2011 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

DESCRIPTION

A/C amp. changes duty ratio of front blower motor control signal to control air flow continuously. When air flow is increased, duty ratio of front blower motor control signal gradually increases to prevent a sudden increase in air flow.
In addition to manual control, air flow control is compose of fan speed control at door motor operation.

FAN SPEED CONTROL AT DOOR MOTOR OPERATION

When front mode door motor is activated while air flow is more than the specified value, A/C amp. reduces temporarily fan speed so that front mode door moves smoothly.