Rear Window Defogger Power Supply 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 FUSE
Check if any of the following fuses for fuse block (J/B) and IPDM E/R are blown.

Fig 1: Fuses Reference Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

NOTE: Refer to "COMPONENT PARTS AND HARNESS CONNECTOR LOCATION ".

OK or NG
- OK: GO TO 2.
- NG: If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse, refer to "COMPONENT PARTS AND HARNESS CONNECTOR LOCATION ".
CHECK REAR WINDOW DEFOGGER RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear window defogger relay.
3. Turn ignition switch ON.
4. Check voltage between rear window defogger relay connector and ground.
OK or NG
- OK: GO TO 3.
- NG: Repair or replace harness.
  
  Fig 2: Terminals Voltage Reference Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 3: Checking Voltage Between Rear Window Defogger Relay Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK REAR WINDOW DEFOGGER RELAY
Check continuity between rear window defogger terminals 3 and 5, 6 and 7.

Fig 4: Terminals Continuity Reference Chart
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 5: Checking Continuity Between Rear Window Defogger Terminals 3 And 5, 6 And 7
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG
- OK: GO TO 4.
- NG: Replace rear window defogger relay.
CHECK REAR WINDOW DEFOGGER RELAY GROUND CIRCUIT
1. Install rear window defogger relay.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R connector and ground.
  
  Fig 6: Terminals Voltage Reference Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 7: Checking Voltage Between IPDM E/R Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: Rear window defogger power supply circuit check is OK.
- NG: GO TO 5.
CHECK IPDM E/R HARNESS
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R and rear window defogger relay.
3. Check continuity between IPDM E/R connector E121 terminal 52 and rear window defogger relay connector B4 terminal 2.
  52 (G/R) - 2 (G/R): Continuity should exist .
OK or NG
- OK: GO TO 6.
- NG: Repair or replace harness.
  
  Fig 8: Checking Continuity Between IPDM E/R Connector E121 Terminal 52 And Rear Window Defogger Relay Connector B4 Terminal 2
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK REAR WINDOW DEFOGGER RELAY OUTPUT SIGNAL
1. Connect IPDM E/R and rear window defogger relay.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R connector E121 terminal 52 and ground.
  52 (G/R) - Ground: Battery voltage
OK or NG
- OK: Replace IPDM E/R. Refer to REMOVAL AND INSTALLATION OF IPDM E/R .
- NG: Repair or replace harness.
  
  Fig 9: Checking Voltage Between IPDM E/R Connector E121 Terminal 52 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.