1998 Nissan-Datsun Sentra BaseFACTORY OEM SERVICE PROCEDURE

Electrical Load: 240SX

  1. Turn ignition off. Disconnect PCM harness connector. Turn ignition on. Measure voltage between ground and PCM harness connector terminal No. 55 (Blue/Red wire). See Figure. With rear window defogger on, battery voltage should exist. With rear window defogger off, zero volts should exist. If voltage is not as specified, go to step 3). If voltage is as specified, go to next step.
  2. Measure voltage between ground and PCM harness connector terminal No. 60 (Red/Yellow wire). With headlight switch on, battery voltage should exist. With headlight switch off, zero volts should exist. If voltage is not as specified, go to next step. If voltage is as specified, system is functioning normally.
  3. Turn ignition off. Check rear window defogger for correct operation. See REAR WINDOW DEFOGGERS article in the ACCESSORIES/SAFETY EQUIP section. If rear window defogger operates normally, go to next step. If rear window defogger does not operate normally, repair as necessary.
  4. Disconnect rear window defogger and headlight switch harness connectors. Check continuity between PCM harness connector terminal No. 55 (Blue/Red wire) and rear window defogger relay terminal No. 5. See Figure. Also check continuity between PCM harness connector terminal No. 60 (Red/Yellow wire) and headlight switch harness connector terminal No. 10. Continuity should exist. If continuity exists, go to next step. If continuity does not exist, check and repair appropriate wire between PCM and relay. Also check fuses and harness connector terminals for pushed-out, bent, damaged or corroded terminals. See WIRING DIAGRAMS article.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.