5. Check Motor Ground Circuit

WARNING: This page is about a different car, the 2004 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

Turn ignition switch OFF.
Disconnect door motor connector.
Check continuity between mode door motor harness connector M40 terminal 2 (B), driver side air mix door motor harness connector M39 terminal 2 (B), passenger side air mix door motor harness connector M87 terminal 2 (B), intake door motor harness connector M58 terminal 2 (B) and ground. See Fig 1.
1. 2 - Ground : Continuity should exist.

OK or NG

OK, GO TO 6 .
NG, Repair harness or connector.

Fig 1: Identifying Door Motor Connector Terminals

Courtesy of NISSAN MOTOR CO., U.S.A.