Rear Window Defogger Switch Circuit Check

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.

CHECK REAR WINDOW DEFOGGER SWITCH OPERATION
With CONSULT-II

Check ("REAR DEF SW", "IGN ON SW") in DATA MONITOR mode with CONSULT-II.
- When rear window defogger switch is turned to ON REAR DEF SW: ON
- When ignition switch is turned to ON IGN ON SW: ON
Fig 1: CONSULT-II Screen Display - DATA MONITOR
Courtesy of NISSAN MOTOR CO., U.S.A.

Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between BCM connector ground.
  
  Fig 2: Checking Voltage Between BCM Connector Terminal 9 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Terminals Voltage Reference Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: Rear window defogger switch check is OK.
- NG: GO TO 2.
CHECK REAR WINDOW DEFOGGER SWITCH CIRCUIT HARNESS CONTINUITY
1. Turn ignition switch OFF.
2. Disconnect BCM and front air control.
3. Check continuity between BCM connector M18 terminal 9 and front air control connector M49 terminal 11.
  
  Fig 4: Checking Continuity Between BCM Connector M18 Terminal 9 And Front Air Control Connector M49 Terminal 11 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  - 9 (W/L) - 11 (W/L): Continuity should exist.
4. Check continuity between BCM connector M18 terminal 9 and ground
  - 9 (W/L) - Ground: Continuity should not exist.
OK or NG
- OK: GO TO 3.
- NG: Repair or replace harness.
CHECK BCM OUTPUT SIGNAL
1. Connect BCM.
2. Turn ignition switch ON.
3. Check voltage between BCM connector M18 terminal 9 and ground.
  
  Fig 5: Checking Voltage Between BCM Connector M18 Terminal 9 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  - 9 (W/L) - Ground: Approx. 5
OK or NG
- OK: Replace front air control. Refer to "CONTROL UNIT ".
- NG: Replace BCM. Refer to "REMOVAL AND INSTALLATION OF BCM ".