The usual problem when ac air or heat doesn't flow from the vents even when turned on is a bad blower motor resistor.
the pics are that of the 1995 altima but are typical of the flocks.
naturally the resistor is located next to the blower motor, under the glove compartment, and held by 2 bolts.
they are easy and cheap to replace and can be gotten cheapest by rockauto.com
Tuesday, August 25th, 2009 AT 7:49 PM