Rear Window Defogger Power Supply 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 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.
  
  Fig 2: Checking Voltage Between Rear Window Defogger Relay Connector Terminals 1, 3, 6 & 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: GO TO 3.
- NG: Repair or replace harness.
CHECK REAR WINDOW DEFOGGER RELAY
Check continuity between rear window defogger relay terminals 3 and 5, 6 and 7.

Fig 4: Checking Continuity Between Rear Window Defogger Terminal 3 And Terminals 5, 6 & 7
Courtesy of NISSAN MOTOR CO., U.S.A.

Fig 5: Terminals Continuity Reference Chart
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 E121 terminal 52 and ground.
  
  Fig 6: Checking Voltage Between IPDM E/R Connector E121 Terminal 52 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 7: Terminals Voltage Reference Chart
  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 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.
- NG: Repair or replace harness.
  
  Fig 9: Checking Voltage Between IPDM E/R Connector E121 Terminal 52 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.