Rear Window Defogger Circuit Check

WARNING: This page is about a different car, the 2004 Infiniti G35. 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 rear window defogger connector.
3. Turn ignition switch ON.
4. Check voltage between rear window defogger connector and ground.
  
  Fig 1: Checking Rear Window Defogger Connector Voltage
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 2: Rear Window Defogger Voltage Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: GO TO 2.
2. NG: GO TO 3 .
Check Rear Window Defogger Ground Circuit
1. Turn ignition switch OFF.
2. Check continuity between rear window defogger connector B241 terminal 1 and ground.
  
  Fig 3: Checking Continuity At Rear Window Defogger Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. 1 (B) - Ground: Continuity should exist
OK or NG
1. 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.
2. NG: Repair or replace harness between rear window defogger and ground.
Check Rear Window Defogger Power Window Supply Circuit 2
1. Turn ignition switch OFF.
2. Disconnect rear window defogger connector.
3. Turn ignition switch ON.
4. Check voltage between rear window defogger connector and ground.
  
  Fig 4: Checking Voltage At Rear Window Defogger Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 5: Rear Window Defogger Voltage Specifications
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
1. OK: Repair or replace harness between condenser and rear window defogger.
2. NG: GO TO 4.
Check Condenser Harness
1. Turn ignition switch OFF.
2. Disconnect rear window defogger relay.
3. Check continuity between rear window defogger relay connector B109 terminal 5 and condenser connector B34 terminal 1.
  
  Fig 6: Checking Continuity Between Rear Window Defogger Relay And Condenser
  Courtesy of NISSAN MOTOR CO., U.S.A.
  1. 5 (B/W) -1 (B/W): Continuity should exist.
OK or NG
1. OK: Check the condition of the harness and the connector.
2. NG: Repair or replace harness rear window defogger relay and condenser.