Rear Window Defogger Circuit Check

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.

CHECK REAR WINDOW DEFOGGER POWER SUPPLY CIRCUIT 1
1. Turn ignition switch OFF.
2. Disconnect condenser.
3. Turn ignition switch ON.
4. Check voltage between condenser connector and ground.
  
  Fig 1: Terminals Voltage Reference Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 2: Checking Voltage Between Condenser Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: GO TO 2.
- NG: GO TO 3.
CHECK REAR WINDOW DEFOGGER GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between rear window defogger connector B351 terminal - and ground.
  -(B) - Ground: Continuity should exist.
OK or NG
- OK: Check filament. Refer to "FILAMENT CHECK ".
  - If filament is OK. Check the condition of the harness and the connector.
  - If filament is NG. Repair filament.
- NG: Repair or replace harness.
  
  Fig 3: Checking Continuity Between Rear Window Defogger Connector B351 Terminal - And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK CONDENSER HARNESS
1. Turn ignition switch OFF.
2. Disconnect rear window defogger relay.
3. Check continuity between rear window defogger relay connector B4 terminal 5 and condenser connector B21 terminal 1.
  5 (G) - 1 (G): Continuity should exist.
OK or NG
- OK: Check the condition of the harness and the connector.
- NG: Repair or replace harness.
  
  Fig 4: Checking Continuity Between Rear Window Defogger Relay Connector B4 Terminal 5 And Condenser Connector B21 Terminal 1
  Courtesy of NISSAN MOTOR CO., U.S.A.