Diagnostic Procedure For A/C System

WARNING: This page is about a different car, the 2005 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

SYMPTOM: A/C system does not come on.

Fig 1: A/C System Diagram

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

CHECK POWER SUPPLY CIRCUITS FOR FRONT AIR CONTROL
1. Disconnect front air control connector.
2. Check voltage between front air control harness connector M49 terminals 14 (G/Y) and 22 (Y/R), and ground.
  
  Fig 2: Terminal Ignition Switch Position Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Checking Voltage Between Front Air Control Harness Connector Terminals 14, 22 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 2.
- NG: Check 10A and 15A fuses [Nos. 2 and 19, located in the fuse block (J/B)]. Refer to "FUSE BLOCK-JUNCTION BOX(J/B) ".
  - If fuses are OK, check harness for open circuit. Repair or replace as necessary.
  - If fuses are NG, replace fuse and check harness for short circuit. Repair or replace as necessary.
CHECK GROUND CIRCUIT FOR FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Check continuity between front air control harness connector M49 terminal 1 (B) and ground.
  
  Fig 4: Checking Continuity Between Front Air Control Harness Connector Terminal 1 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
- Continuity should exist.
OK or NG
- OK: Replace front air control. Refer to "FRONT AIR CONTROL ".
- NG: Repair harness or connector.